diff --git a/4champ/Data/Structs.swift b/4champ/Data/Structs.swift
index 8b75243..c668657 100644
--- a/4champ/Data/Structs.swift
+++ b/4champ/Data/Structs.swift
@@ -112,7 +112,7 @@ struct MMD: Identifiable {
 }
 
 extension MMD: Equatable {}
-func ==(lhs: MMD, rhs: MMD) -> Bool {
+func == (lhs: MMD, rhs: MMD) -> Bool {
   let eq = lhs.id == rhs.id && lhs.id != nil
   return eq
 }
diff --git a/4champ/Networking/ModuleFetcher.swift b/4champ/Networking/ModuleFetcher.swift
index c1748bf..9005937 100644
--- a/4champ/Networking/ModuleFetcher.swift
+++ b/4champ/Networking/ModuleFetcher.swift
@@ -29,7 +29,7 @@ enum FetcherError: Error {
  ModuleFetcher state delegate.
  Implemented in classes that use a fetcher to download modules, e.g. RadioInteractor and SearchInteractor
  */
-protocol ModuleFetcherDelegate {
+protocol ModuleFetcherDelegate: class {
   /**
    Fetcher calls delegate on state changes.
    - parameters:
@@ -166,8 +166,7 @@ class ModuleFetcher {
    - returns: module data, unzipped
   */
   private func gzipInflate(data: Data) -> Data? {
-    if data.isGzipped {
-      let inflated = try! data.gunzipped()
+    if data.isGzipped, let inflated = try? data.gunzipped() {
       return inflated
     }
     log.error("FAILED TO UNZIP")
diff --git a/4champ/Replay/ModulePlayer.swift b/4champ/Replay/ModulePlayer.swift
index fe414ba..b16726c 100644
--- a/4champ/Replay/ModulePlayer.swift
+++ b/4champ/Replay/ModulePlayer.swift
@@ -275,15 +275,13 @@ class ModulePlayer: NSObject {
   
   /// called when app resigns to clear non-stored modules
   func cleanup() {
-    for mod in playQueue {
-      if mod.hasBeenSaved() == false {
-        if let url = mod.localPath {
-          log.info("Deleting module \(url.lastPathComponent)")
-          do {
-            try FileManager.default.removeItem(at: url)
-          } catch {
-            log.error("Deleting file at \(url) failed, \(error)")
-          }
+    for mod in playQueue where !mod.hasBeenSaved() {
+      if let url = mod.localPath {
+        log.info("Deleting module \(url.lastPathComponent)")
+        do {
+          try FileManager.default.removeItem(at: url)
+        } catch {
+          log.error("Deleting file at \(url) failed, \(error)")
         }
       }
     }
@@ -333,10 +331,8 @@ extension ModulePlayer: ModuleStorageObserver {
       currentModule?.favorite = mmd.favorite
     }
     if playQueue.count == 0 { return }
-    for i in 0...playQueue.count-1 {
-      if playQueue[i] == mmd {
-        playQueue[i].favorite = mmd.favorite
-      }
+    for qIndex in 0...playQueue.count-1 where playQueue[qIndex] == mmd {
+      playQueue[qIndex].favorite = mmd.favorite
     }
     _ = observers.map {
       $0.queueChanged(changeType: .other)
diff --git a/4champ/Scenes/About/AboutViewController.swift b/4champ/Scenes/About/AboutViewController.swift
index dae50d9..5bab17c 100644
--- a/4champ/Scenes/About/AboutViewController.swift
+++ b/4champ/Scenes/About/AboutViewController.swift
@@ -80,7 +80,6 @@ class AboutViewController: UIViewController, AboutDisplayLogic {
 
   // MARK: Display Logic
   func displayNowPlaying(_ viewModel: About.Status.ViewModel) {
-    // TODO
   }
 
   @objc func reviewNow() {
diff --git a/4champ/Scenes/Local/LocalInteractor.swift b/4champ/Scenes/Local/LocalInteractor.swift
index 8b636c7..46c8575 100644
--- a/4champ/Scenes/Local/LocalInteractor.swift
+++ b/4champ/Scenes/Local/LocalInteractor.swift
@@ -61,7 +61,11 @@ class LocalInteractor: NSObject, LocalBusinessLogic, LocalDataStore {
     fetchRequest.predicate = NSPredicate.init(format: filterString)
     frc = moduleStorage.createFRC(fetchRequest: fetchRequest, entityName: "ModuleInfo")
     frc?.delegate = self
-    try! frc?.performFetch()
+    do {
+      try frc?.performFetch()
+    } catch {
+      log.error("Fetch failed \(error)")
+    }
     presenter?.presentModules(response: Local.SortFilter.Response())
   }
   
diff --git a/4champ/Scenes/Local/ModuleStorage.swift b/4champ/Scenes/Local/ModuleStorage.swift
index a37d7c0..ce3298a 100644
--- a/4champ/Scenes/Local/ModuleStorage.swift
+++ b/4champ/Scenes/Local/ModuleStorage.swift
@@ -118,7 +118,7 @@ class ModuleStorage: NSObject {
     let filterString = "plId == 'default'"
     fetchRequest.predicate = NSPredicate.init(format: filterString)
     let frc = createFRC(fetchRequest: fetchRequest, entityName: "Playlist")
-    try! frc.performFetch()
+    try? frc.performFetch()
     guard let defaultPl = frc.fetchedObjects?.first else {
       // No Default playlist yet, must create it
       return createPlaylist(name: "default", id: "default")
diff --git a/4champ/Scenes/MainViewController.swift b/4champ/Scenes/MainViewController.swift
index 53849dc..e025a53 100644
--- a/4champ/Scenes/MainViewController.swift
+++ b/4champ/Scenes/MainViewController.swift
@@ -65,9 +65,9 @@ class MainViewController: UITabBarController {
     npView?.addGestureRecognizer(lpr)
 
     let titles = ["TabBar_Local", "TabBar_Playlist", "TabBar_Search", "TabBar_Radio", "TabBar_About"]
-    for t in tabBar.items! {
-      if let index = tabBar.items!.index(of: t) {
-        t.title = titles[index].l13n()
+    for tab in tabBar.items! {
+      if let index = tabBar.items!.index(of: tab) {
+        tab.title = titles[index].l13n()
       }
     }
   }
@@ -96,13 +96,10 @@ class MainViewController: UITabBarController {
         switch event.subtype {
         case .remoteControlPlay:
           modulePlayer.resume()
-          break
         case .remoteControlPause:
           modulePlayer.pause()
-          break
         case .remoteControlStop:
           modulePlayer.stop()
-          break
         case .remoteControlNextTrack:
           modulePlayer.playNext()
         case .remoteControlPreviousTrack:
diff --git a/4champ/Scenes/PlaylistSelector/PlaylistSelectorInteractor.swift b/4champ/Scenes/PlaylistSelector/PlaylistSelectorInteractor.swift
index 65f890b..17fc40c 100644
--- a/4champ/Scenes/PlaylistSelector/PlaylistSelectorInteractor.swift
+++ b/4champ/Scenes/PlaylistSelector/PlaylistSelectorInteractor.swift
@@ -37,7 +37,7 @@ class PlaylistSelectorInteractor: PlaylistSelectorBusinessLogic, PlaylistSelecto
     let filterString = "plId != 'radioList'"
     fetchRequest.predicate = NSPredicate.init(format: filterString)
     frc = moduleStorage.createFRC(fetchRequest: fetchRequest, entityName: "Playlist")
-    try! frc?.performFetch()
+    try? frc?.performFetch()
     
     if let plObjects = frc?.fetchedObjects {
       var plMetaData = plObjects.map {
@@ -46,7 +46,7 @@ class PlaylistSelectorInteractor: PlaylistSelectorBusinessLogic, PlaylistSelecto
       
       for pl in plObjects {
         for mi in pl.modules ?? [] {
-          let modId = (mi as! ModuleInfo).modId?.intValue ?? 0
+          let modId = (mi as? ModuleInfo)?.modId?.intValue ?? 0
           if let index = plMetaData.firstIndex(where: { $0.id == pl.plId }) {
             plMetaData[index].modules.append(modId)
           }
@@ -86,7 +86,7 @@ class PlaylistSelectorInteractor: PlaylistSelectorBusinessLogic, PlaylistSelecto
       moduleStorage.saveContext()
       presenter?.presentAppend(response: completed)
     } else {
-      if let _ = module?.localPath {
+      if module?.localPath != nil {
         // 2. Module is downloaded (radio/search) but not yet in database
         moduleStorage.addModule(module: module!)
         if let modInfo = moduleStorage.fetchModuleInfo(modId) {
@@ -112,7 +112,7 @@ class PlaylistSelectorInteractor: PlaylistSelectorBusinessLogic, PlaylistSelecto
     let filterString = "plId == '\(id)'"
     fetchRequest.predicate = NSPredicate.init(format: filterString)
     let tmp = moduleStorage.createFRC(fetchRequest: fetchRequest, entityName: "Playlist")
-    try! tmp.performFetch()
+    try? tmp.performFetch()
     return tmp.fetchedObjects?.first
   }
 }
diff --git a/4champ/Scenes/PlaylistSelector/PlaylistSelectorPresenter.swift b/4champ/Scenes/PlaylistSelector/PlaylistSelectorPresenter.swift
index 4966f95..b6f266e 100644
--- a/4champ/Scenes/PlaylistSelector/PlaylistSelectorPresenter.swift
+++ b/4champ/Scenes/PlaylistSelector/PlaylistSelectorPresenter.swift
@@ -44,8 +44,8 @@ class PlaylistSelectorPresenter: PlaylistSelectorPresentationLogic {
         }
 
         var moduleName = response.module.name ?? ""
-        if let mod_name = response.module.name, let composer_name = response.module.composer, composer_name.count > 0 {
-            moduleName = String.init(format: "LockScreen_Playing".l13n(), mod_name, composer_name)
+        if let mName = response.module.name, let cName = response.module.composer, cName.count > 0 {
+            moduleName = String.init(format: "LockScreen_Playing".l13n(), mName, cName)
         }
         
         let status: DownloadStatus = response.module.hasBeenSaved() ? .complete : .unknown
diff --git a/4champ/Scenes/PlaylistSelector/PlaylistSelectorStore.swift b/4champ/Scenes/PlaylistSelector/PlaylistSelectorStore.swift
index 4e2537a..eadc4cb 100644
--- a/4champ/Scenes/PlaylistSelector/PlaylistSelectorStore.swift
+++ b/4champ/Scenes/PlaylistSelector/PlaylistSelectorStore.swift
@@ -23,7 +23,7 @@ class PlaylistSelectorStore: ObservableObject, PlaylistSelectorDisplayLogic {
   weak var hostingController: UIHostingController<PlaylistPickerView>?
   
   @Published var viewModel: PlaylistSelector.PrepareSelection.ViewModel
-
+  
   init() {
     self.viewModel = PlaylistSelector.PrepareSelection.ViewModel(module: "<rnd>", currentPlaylistIndex: 0, playlistOptions: [], status: .unknown)
   }
@@ -32,16 +32,16 @@ class PlaylistSelectorStore: ObservableObject, PlaylistSelectorDisplayLogic {
     let pls = PlaylistSelectorStore()
     var contentView = PlaylistPickerView(dismissAction: { pls.hostingController?.dismiss(animated: true, completion: nil)},
                                          shareAction: {
-                                          pls.shareModule(module)
+      pls.shareModule(module)
     },
                                          deleteAction: {
-                                          pls.deleteModule(module)
+      pls.deleteModule(module)
     },
                                          store: pls)
     pls.setup()
     pls.doPrepare(mod: module)
-    contentView.addToPlaylistAction = { b in
-        pls.addToPlaylist(playlistIndex: b)
+    contentView.addToPlaylistAction = { pIndex in
+      pls.addToPlaylist(playlistIndex: pIndex)
     }
     let hvc = UIHostingController(rootView: contentView)
     pls.hostingController = hvc
@@ -93,7 +93,7 @@ class PlaylistSelectorStore: ObservableObject, PlaylistSelectorDisplayLogic {
     guard viewModel.status == .complete else {
       return
     }
-
+    
     interactor?.deleteModule(request: PlaylistSelector.Delete.Request(module: module))
     hostingController?.dismiss(animated: true, completion: nil)
   }
diff --git a/4champ/Scenes/Playlists/PlaylistInteractor.swift b/4champ/Scenes/Playlists/PlaylistInteractor.swift
index 5fa17b1..e2f479b 100644
--- a/4champ/Scenes/Playlists/PlaylistInteractor.swift
+++ b/4champ/Scenes/Playlists/PlaylistInteractor.swift
@@ -33,19 +33,23 @@ class PlaylistInteractor: NSObject, PlaylistBusinessLogic, PlaylistDataStore {
   var selectedPlaylistId: String?
   var frc: NSFetchedResultsController<Playlist>?
   // var name: String = ""
-
+  
   private var downloadController = DownloadController.init()
   
   override init() {
     super.init()
     let filterString = "plId != 'radioList'"
-
+    
     let fetchRequest = NSFetchRequest<Playlist>.init(entityName: "Playlist")
     fetchRequest.sortDescriptors = []
     fetchRequest.predicate = NSPredicate.init(format: filterString)
     frc = moduleStorage.createFRC(fetchRequest: fetchRequest, entityName: "Playlist")
     frc?.delegate = self
-    try! frc?.performFetch()
+    do {
+      try frc?.performFetch()
+    } catch {
+      log.error("Failed to perform fetch: \(error)")
+    }
     
     if selectedPlaylistId == nil {
       selectedPlaylistId = "default"
@@ -125,11 +129,12 @@ class PlaylistInteractor: NSObject, PlaylistBusinessLogic, PlaylistDataStore {
   private func rebuildQueue() {
     if let pl = frc?.fetchedObjects?.first(where: { ($0 as Playlist).plId == selectedPlaylistId }) {
       var playlistQueue: [MMD] = []
-      if let moduleinfos = pl.modules {
-        for mod in moduleinfos {
-          playlistQueue.append(MMD(cdi: (mod as! ModuleInfo)))
+      pl.modules?.forEach {
+        if let modInfo = $0 as? ModuleInfo {
+          playlistQueue.append(MMD(cdi: modInfo))
         }
       }
+      
       if pl.playmode?.boolValue ?? false {
         playlistQueue.shuffle()
       }
@@ -152,14 +157,14 @@ extension PlaylistInteractor: NSFetchedResultsControllerDelegate {
   }
   
   func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {
-
+    
     guard modulePlayer.radioOn == false else {
       return
     }
     
     if let pl = anObject as? Playlist, pl.plId == selectedPlaylistId {
       rebuildQueue()
-    }    
+    }
   }
   
   func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
diff --git a/4champ/Scenes/Playlists/PlaylistPresenter.swift b/4champ/Scenes/Playlists/PlaylistPresenter.swift
index 09c8939..1ecad96 100644
--- a/4champ/Scenes/Playlists/PlaylistPresenter.swift
+++ b/4champ/Scenes/Playlists/PlaylistPresenter.swift
@@ -25,9 +25,9 @@ class PlaylistPresenter: PlaylistPresentationLogic {
     let shuffle = (pl.playmode?.intValue ?? 0) == 1
 
     var mods: [MMD] = []
-    if let moduleinfos = pl.modules {
-      for mod in moduleinfos {
-        mods.append(MMD(cdi: (mod as! ModuleInfo)))
+    pl.modules?.forEach {
+      if let modInfo = $0 as? ModuleInfo {
+        mods.append(MMD(cdi: modInfo))
       }
     }
       
diff --git a/4champ/Scenes/Playlists/PlaylistView.swift b/4champ/Scenes/Playlists/PlaylistView.swift
index 9c2874d..e886e9a 100644
--- a/4champ/Scenes/Playlists/PlaylistView.swift
+++ b/4champ/Scenes/Playlists/PlaylistView.swift
@@ -51,7 +51,7 @@ struct SUIModule: View {
 
 struct PlaylistView: View {
     @Environment(\.managedObjectContext) var managedObjectContext
-    @State private var show_modal: Bool = false
+    @State private var showModal: Bool = false
     @State var showNowPlaying: Bool = false
     @State var isEditing: Bool = false
     @State var navigationButtonID = UUID()
@@ -93,13 +93,13 @@ struct PlaylistView: View {
     var body: some View {
         VStack {
             Button(action: {
-                self.show_modal = true
+                self.showModal = true
             }) {
                 Text(store.viewModel.playlistName).underline()
                     .foregroundColor(Color(.white))
                     .padding(EdgeInsets.init(top: 5, leading: 0, bottom: -5, trailing: 0))
-            }.sheet(isPresented: self.$show_modal) {
-                PlaylistSelectorSUI(show_modal: self.$show_modal).environment(\.managedObjectContext, self.managedObjectContext).onDisappear {
+            }.sheet(isPresented: self.$showModal) {
+                PlaylistSelectorSUI(showModal: self.$showModal).environment(\.managedObjectContext, self.managedObjectContext).onDisappear {
                     self.navigationButtonID = UUID()
                 }.background(Color(Appearance.darkBlueColor))
             }
@@ -171,7 +171,7 @@ func randomMMD() -> MMD {
 var st = PlaylistStore(viewModel: Playlists.Select.ViewModel(playlistName: "foo", shuffle: false, modules: [randomMMD(), randomMMD(), randomMMD()])
 )
 
-struct Playlist_Preview: PreviewProvider {
+struct PlaylistPreview: PreviewProvider {
     static var previews: some View {
         Group {
             NavigationView {
diff --git a/4champ/Scenes/Playlists/SelectPlaylistView.swift b/4champ/Scenes/Playlists/SelectPlaylistView.swift
index 461ee6a..0c00d1b 100644
--- a/4champ/Scenes/Playlists/SelectPlaylistView.swift
+++ b/4champ/Scenes/Playlists/SelectPlaylistView.swift
@@ -41,7 +41,7 @@ struct PlaylistCell: View {
 }
 
 struct PlaylistSelectorSUI: View {
-    @Binding var show_modal: Bool
+    @Binding var showModal: Bool
     @State private var listId = UUID()
     @Environment(\.managedObjectContext) var managedObjectContext
     @FetchRequest(entity: Playlist.entity(),
@@ -126,7 +126,7 @@ struct PlaylistSelectorSUI: View {
                         if pl.plName != "radioList" {
                             PlaylistCell(pl: pl).contentShape(Rectangle()).onTapGesture {
                                 moduleStorage.currentPlaylist = pl
-                                self.show_modal.toggle()
+                                self.showModal.toggle()
                             }
                             .onLongPressGesture {
                                 self.edit(pl: pl)
@@ -136,7 +136,7 @@ struct PlaylistSelectorSUI: View {
                 }.contentShape(Rectangle()).id(listId)
             }.navigationBarTitle("PlaylistView_Playlists", displayMode: .inline)
                 .navigationBarItems(leading: Button(action: {
-                    self.show_modal.toggle()
+                    self.showModal.toggle()
                 }) {
                     Image(systemName: "xmark").imageScale(.large)
                     },
diff --git a/4champ/Scenes/Radio/RadioInteractor.swift b/4champ/Scenes/Radio/RadioInteractor.swift
index ba3dd0e..7b9b540 100644
--- a/4champ/Scenes/Radio/RadioInteractor.swift
+++ b/4champ/Scenes/Radio/RadioInteractor.swift
@@ -325,7 +325,7 @@ class RadioInteractor: NSObject, RadioBusinessLogic, RadioDataStore, RadioRemote
       while(id == 0 || !radioSessionHistory.filter({ mmd in
         mmd.id == id
       }).isEmpty) {
-        id = Int(arc4random_uniform(UInt32(settings.collectionSize)))
+        id = Int.random(in: 1...settings.collectionSize)
       }
       return id
     case .new:
@@ -333,7 +333,7 @@ class RadioInteractor: NSObject, RadioBusinessLogic, RadioDataStore, RadioRemote
         lastPlayed = settings.collectionSize
         settings.newestPlayed = lastPlayed
       } else {
-        lastPlayed = lastPlayed - 1
+        lastPlayed -= 1
       }
       return lastPlayed
     case .local:
@@ -375,26 +375,30 @@ extension RadioInteractor: ModuleFetcherDelegate {
       status = .fetching(progress: progress)
       
     case .done(let mmd):
-      switch postFetchAction {
-      case .appendToQueue:
-        modulePlayer.playQueue.append(mmd)
-      case .insertToQueue:
-        modulePlayer.playQueue.insert(mmd, at: 0)
-      case .startPlay:
-        modulePlayer.play(mmd: mmd)
-      }
-      postFetchAction = .appendToQueue // reset to default
-      
-      self.triggerBufferPresentation()
-      if let first = modulePlayer.playQueue.first, first == mmd {
-        modulePlayer.play(at: 0)
-      }
-      self.fillBuffer()
-      self.status = .on
+      handleDownloadComplete(mmd)
       
     default: ()
     }
   }
+  
+  func handleDownloadComplete(_ mmd: MMD) {
+    switch postFetchAction {
+    case .appendToQueue:
+      modulePlayer.playQueue.append(mmd)
+    case .insertToQueue:
+      modulePlayer.playQueue.insert(mmd, at: 0)
+    case .startPlay:
+      modulePlayer.play(mmd: mmd)
+    }
+    postFetchAction = .appendToQueue // reset to default
+    
+    self.triggerBufferPresentation()
+    if let first = modulePlayer.playQueue.first, first == mmd {
+      modulePlayer.play(at: 0)
+    }
+    self.fillBuffer()
+    self.status = .on
+  }
 }
 
 extension RadioInteractor: ModulePlayerObserver {
diff --git a/4champ/Scenes/Search/SearchViewController.swift b/4champ/Scenes/Search/SearchViewController.swift
index d418e3e..b1a9626 100644
--- a/4champ/Scenes/Search/SearchViewController.swift
+++ b/4champ/Scenes/Search/SearchViewController.swift
@@ -174,7 +174,7 @@ class SearchViewController: UIViewController, SearchDisplayLogic {
       var onlineOnly = vm.modules.count
       for mod in vm.modules {
         if mod.hasBeenSaved() || mod.supported() == false {
-          onlineOnly = onlineOnly - 1
+          onlineOnly -= 1
         }
       }
       
@@ -523,7 +523,9 @@ extension SearchViewController: ModuleCellDelegate {
   
   func shareTapped(cell: ModuleCell) {
     guard let ip = tableView?.indexPath(for: cell),
-      let module = viewModel?.modules[ip.row], let _ = module.id, module.supported() else {
+          let module = viewModel?.modules[ip.row],
+          module.id != nil,
+          module.supported() else {
         return
     }
     shareUtil.shareMod(mod: module)
@@ -541,7 +543,6 @@ extension SearchViewController: ModuleCellDelegate {
   }
   
   func addAction(moduleId: Int, playlistId: String) {
-    log.error("addAction")
-    // TODO: Add the module to playlist
+    log.error("not expecting addAction")
   }
 }
diff --git a/4champ/Scenes/Settings/SettingsInteractor.swift b/4champ/Scenes/Settings/SettingsInteractor.swift
index 0aaff9d..646959d 100644
--- a/4champ/Scenes/Settings/SettingsInteractor.swift
+++ b/4champ/Scenes/Settings/SettingsInteractor.swift
@@ -17,7 +17,7 @@ protocol SettingsDataStore {
 }
 
 class SettingsInteractor: SettingsBusinessLogic, SettingsDataStore {
-
+  
   private enum SettingKeys {
     static let domainName = "DomainName"
     static let stereoSeparation = "StereoSeparation"
@@ -26,81 +26,81 @@ class SettingsInteractor: SettingsBusinessLogic, SettingsDataStore {
     static let prevCollectionSize = "prevCollectionSize"
     static let interpolation = "interpolation"
   }
-
+  
   var presenter: SettingsPresentationLogic?
   
   var stereoSeparation: Int {
-    set {
-        UserDefaults.standard.set(newValue, forKey: SettingKeys.stereoSeparation)
-    }
     get {
       if let value = UserDefaults.standard.value(forKey: SettingKeys.stereoSeparation) as? Int {
         return value
       }
       return Constants.stereoSeparationDefault
     }
+    set {
+      UserDefaults.standard.set(newValue, forKey: SettingKeys.stereoSeparation)
+    }
+  }
+  
+  var interpolation: SampleInterpolation {
+    get {
+      if let value = UserDefaults.standard.value(forKey: SettingKeys.interpolation) as? Int {
+        return SampleInterpolation(rawValue: value) ?? .libraryDefault
+      }
+      return SampleInterpolation.libraryDefault
+    }
+    set {
+      UserDefaults.standard.set(newValue.rawValue, forKey: SettingKeys.interpolation)
+    }
+  }
+  
+  var collectionSize: Int {
+    get {
+      if let value = UserDefaults.standard.value(forKey: SettingKeys.collectionSize) as? Int {
+        return value
+      }
+      return Constants.latestDummy
+    }
+    set {
+      UserDefaults.standard.set(newValue, forKey: SettingKeys.collectionSize)
+      updateBadge()
+      NotificationCenter.default.post(Notification.init(name: Notifications.badgeUpdate))
+    }
   }
-    
-    var interpolation: SampleInterpolation {
-        set {
-            UserDefaults.standard.set(newValue.rawValue, forKey: SettingKeys.interpolation)
-        }
-        get {
-            if let value = UserDefaults.standard.value(forKey: SettingKeys.interpolation) as? Int {
-                return SampleInterpolation(rawValue: value) ?? .libraryDefault
-            }
-            return SampleInterpolation.libraryDefault
-        }
+  
+  var newestPlayed: Int {
+    get {
+      if let value = UserDefaults.standard.value(forKey: SettingKeys.newestPlayed) as? Int {
+        return value
+      }
+      return 0
     }
-    
-    var collectionSize: Int {
-        set {
-            UserDefaults.standard.set(newValue, forKey: SettingKeys.collectionSize)
-            updateBadge()
-            NotificationCenter.default.post(Notification.init(name: Notifications.badgeUpdate))
-        }
-        get {
-            if let value = UserDefaults.standard.value(forKey: SettingKeys.collectionSize) as? Int {
-                return value
-            }
-            return Constants.latestDummy
-        }
+    set {
+      UserDefaults.standard.set(newValue, forKey: SettingKeys.newestPlayed)
+      updateBadge()
+      NotificationCenter.default.post(Notification.init(name: Notifications.badgeUpdate))
     }
-    
-    var newestPlayed: Int {
-        set {
-            UserDefaults.standard.set(newValue, forKey: SettingKeys.newestPlayed)
-            updateBadge()
-            NotificationCenter.default.post(Notification.init(name: Notifications.badgeUpdate))
-        }
-        get {
-            if let value = UserDefaults.standard.value(forKey: SettingKeys.newestPlayed) as? Int {
-                return value
-            }
-            return 0
-        }
+  }
+  
+  var prevCollectionSize: Int {
+    get {
+      if let value = UserDefaults.standard.value(forKey: SettingKeys.prevCollectionSize) as? Int {
+        return value
+      }
+      return 0
     }
-    
-    var prevCollectionSize: Int {
-        set {
-            UserDefaults.standard.set(newValue, forKey: SettingKeys.prevCollectionSize)
-        }
-        get {
-            if let value = UserDefaults.standard.value(forKey: SettingKeys.prevCollectionSize) as? Int {
-                return value
-            }
-            return 0
-        }
+    set {
+      UserDefaults.standard.set(newValue, forKey: SettingKeys.prevCollectionSize)
     }
-    
-    var badgeCount: Int {
-        if newestPlayed < collectionSize {
-            var diff = collectionSize - newestPlayed
-            diff = diff > Constants.maxBadgeValue ? Constants.maxBadgeValue : diff
-            return diff
-        }
-        return 0
+  }
+  
+  var badgeCount: Int {
+    if newestPlayed < collectionSize {
+      var diff = collectionSize - newestPlayed
+      diff = diff > Constants.maxBadgeValue ? Constants.maxBadgeValue : diff
+      return diff
     }
+    return 0
+  }
   
   // MARK: Do something
   
@@ -111,14 +111,14 @@ class SettingsInteractor: SettingsBusinessLogic, SettingsDataStore {
       stereoSeparation = request.stereoSeparation
       interpolation = request.interpolation
     } else {
-        response = Settings.Update.ValueBag(stereoSeparation: stereoSeparation, interpolation: interpolation)
+      response = Settings.Update.ValueBag(stereoSeparation: stereoSeparation, interpolation: interpolation)
     }
     modulePlayer.setStereoSeparation(stereoSeparation)
     modulePlayer.setInterpolation(interpolation)
     presenter?.presentSettings(response: response)
   }
-    
-    private func updateBadge() {
-        UIApplication.shared.applicationIconBadgeNumber = badgeCount
-    }
+  
+  private func updateBadge() {
+    UIApplication.shared.applicationIconBadgeNumber = badgeCount
+  }
 }
diff --git a/4champ/Scenes/Settings/SettingsViewController.swift b/4champ/Scenes/Settings/SettingsViewController.swift
index 39811d4..92234f5 100644
--- a/4champ/Scenes/Settings/SettingsViewController.swift
+++ b/4champ/Scenes/Settings/SettingsViewController.swift
@@ -114,8 +114,8 @@ class SettingsViewController: UITableViewController, SettingsDisplayLogic {
     
     if let interpolationCell = tableView.cellForRow(at: IndexPath.init(row: 0, section: 1)) as? SettingsInterpolationCell,
       let value = interpolationCell.interpolationSwitch?.isOn {
-      let i = value ? SampleInterpolation.libraryDefault : SampleInterpolation.off
-      valueBag.interpolation = i
+      let ipol = value ? SampleInterpolation.libraryDefault : SampleInterpolation.off
+      valueBag.interpolation = ipol
     }
     
     return valueBag
diff --git a/4champ/Scenes/SharedUI/ModuleCell.swift b/4champ/Scenes/SharedUI/ModuleCell.swift
index 51a2efe..a526a58 100644
--- a/4champ/Scenes/SharedUI/ModuleCell.swift
+++ b/4champ/Scenes/SharedUI/ModuleCell.swift
@@ -75,9 +75,7 @@ extension ModuleCell {
     lbl.textAlignment = .center
     self.contentView.addSubview(lbl)
     DispatchQueue.main.asyncAfter(deadline: DispatchTime.now()+3.0) {
-      UIView.animate(withDuration: 1.0, animations: {lbl.alpha=0}) { (_) in
-        lbl.removeFromSuperview()
-      }
+      UIView.animate(withDuration: 1.0, animations: {lbl.alpha=0}, completion: {_ in lbl.removeFromSuperview()})
     }
   }
 }
diff --git a/4champ/Scenes/Visualizer/AmpSlider.swift b/4champ/Scenes/Visualizer/AmpSlider.swift
index 141ef12..6ff6245 100644
--- a/4champ/Scenes/Visualizer/AmpSlider.swift
+++ b/4champ/Scenes/Visualizer/AmpSlider.swift
@@ -68,11 +68,11 @@ class AmpSlider: UISlider {
         self.setThumbImage(image, for: .highlighted)
     }
     
-    @objc func sliderTapped(_ g: UITapGestureRecognizer) {
+    @objc func sliderTapped(_ gRec: UITapGestureRecognizer) {
         if self.isHighlighted {
             return
         }
-        let pt: CGPoint = g.location(in: self)
+        let pt: CGPoint = gRec.location(in: self)
         let percentage: Float = Float.init(pt.x) / Float.init(self.bounds.size.width)
         let delta: Float = percentage * (self.maximumValue - self.minimumValue)
         let value: Float = self.minimumValue + delta
diff --git a/4champ/Scenes/Visualizer/AmpVizScene.swift b/4champ/Scenes/Visualizer/AmpVizScene.swift
index 08e6e0b..d80c73a 100644
--- a/4champ/Scenes/Visualizer/AmpVizScene.swift
+++ b/4champ/Scenes/Visualizer/AmpVizScene.swift
@@ -73,15 +73,15 @@ class AmpVizScene: SKScene {
     func setupChannelBars() {
         let channelcount = modulePlayer.renderer.numberOfChannels()
         
-        for i in 0..<channelcount {
-            addChannelBar(i, numChannels: channelcount)
+        for cIndex in 0..<channelcount {
+            addChannelBar(cIndex, numChannels: channelcount)
         }
     }
 
     func addChannelBar(_ channel: Int, numChannels: Int) {
-        let w = Int((frame.size.width - 2.0)/CGFloat(numChannels))
-        let ch = AmpVolumeBar.init(rect: CGRect(x: 0, y: 0, width: CGFloat(w) - 2.0, height: frame.size.height))
-        ch.position = CGPoint(x: 2.0 + CGFloat(channel)*CGFloat(w), y: 0)
+        let cWidth = Int((frame.size.width - 2.0)/CGFloat(numChannels))
+        let ch = AmpVolumeBar.init(rect: CGRect(x: 0, y: 0, width: CGFloat(cWidth) - 2.0, height: frame.size.height))
+        ch.position = CGPoint(x: 2.0 + CGFloat(channel)*CGFloat(cWidth), y: 0)
         ch.fillColor = UIColor.clear
         ch.lineWidth = 0
         ch.channel = channel
diff --git a/4champ/Scenes/Visualizer/VisualizerViewController.swift b/4champ/Scenes/Visualizer/VisualizerViewController.swift
index d09e8a0..ee83ad5 100644
--- a/4champ/Scenes/Visualizer/VisualizerViewController.swift
+++ b/4champ/Scenes/Visualizer/VisualizerViewController.swift
@@ -46,11 +46,7 @@ class VisualizerViewController: UIViewController, UIScrollViewDelegate, UIGestur
       if (sender.velocity(in: self.view).y) > 0 {
         self.presentingViewController?.dismiss(animated: true, completion: nil)
       }
-      break
-    default:
-      var v = 0
-      v = v+1
-      // nop
+    default: ()
     }
   }
   
diff --git a/4champ/Utils/ModuleSharing.swift b/4champ/Utils/ModuleSharing.swift
index bb793ad..48a6985 100644
--- a/4champ/Utils/ModuleSharing.swift
+++ b/4champ/Utils/ModuleSharing.swift
@@ -17,7 +17,7 @@ class ShareUtility: NSObject, UIActivityItemSource {
   }
   
   func activityViewController(_ activityViewController: UIActivityViewController, itemForActivityType activityType: UIActivity.ActivityType?) -> Any? {
-    guard let modName = sharedMod?.name, let composer = sharedMod?.composer, let _ = sharedMod?.id else {
+    guard let modName = sharedMod?.name, let composer = sharedMod?.composer, sharedMod?.id != nil else {
       return nil
     }
     let shareString = String.init(format: "Share_DefaultMessage".l13n(), modName, composer)
@@ -25,7 +25,7 @@ class ShareUtility: NSObject, UIActivityItemSource {
   }
   
   func activityViewController(_ activityViewController: UIActivityViewController, subjectForActivityType activityType: UIActivity.ActivityType?) -> String {
-    guard let modName = sharedMod?.name, let composer = sharedMod?.composer, let _ = sharedMod?.id else {
+    guard let modName = sharedMod?.name, let composer = sharedMod?.composer, sharedMod?.id != nil else {
       return ""
     }
     let shareString = String.init(format: "Share_DefaultMessage".l13n(), modName, composer)
diff --git a/4champ/l13n/String+extension.swift b/4champ/l13n/String+extension.swift
index c591f42..5d4b26a 100644
--- a/4champ/l13n/String+extension.swift
+++ b/4champ/l13n/String+extension.swift
@@ -20,8 +20,8 @@ extension String {
   private func fallbackL13N(debugPrefix: String) -> String {
     let fallbackLoc: String
     if let bundlePath = Bundle.main.path(forResource: "en", ofType: "lproj"),
-      let b = Bundle.init(path: bundlePath) {
-      fallbackLoc = b.localizedString(forKey: self, value: "", table: nil)
+      let bundle = Bundle.init(path: bundlePath) {
+      fallbackLoc = bundle.localizedString(forKey: self, value: "", table: nil)
     } else {
       fallbackLoc = self
     }