diff --git a/README.md b/README.md
index e997e18..066ec88 100644
--- a/README.md
+++ b/README.md
@@ -1,17 +1,37 @@
-[中文文档](README_cn.md)
-
+# [中文文档](README_cn.md)
 
 # Features:
 
-1. You can add any custom view on the pip window;
-2. You can hide speed button, backward button, play button and progress bar on the pip window;
-3. You can modify the pip window’s shape dynamically with code;
-4. You can rotate the pip window with code;
-5. You can take photos and record a video while using pip;
-6. The screen would not turn dark when you take photos or record videos;
-7. Timer would never stop while taking photos or recording videos;
-8. The timer's accuracy is millisecond;
-9. The solution for your app rejected by Apple.
+### 1. You can add any custom view on the pip window.
+
+```swift
+func pictureInPictureControllerWillStartPictureInPicture(_ pictureInPictureController: AVPictureInPictureController) {
+    // note this is first window
+    if let window = UIApplication.shared.windows.first {
+        window.addSubview(customView)
+        // use autoLayout
+        customView.snp.makeConstraints { (make) -> Void in
+            make.edges.equalToSuperview()
+        }
+    }
+}
+```
+
+### 2. You can hide speed button, backward button, play button and progress bar on the pip window.
+https://stackoverflow.com/questions/67528832/how-to-hide-system-controls-on-avpictureinpicturecontrollers-float-window#67528832
+
+### 3. You can modify the pip window’s shape dynamically with code.
+
+**The shape of the pip window depends on the shape of video**. So just change current video to a video with a different shape.
+
+Sample code like:
+
+```objective-c
+NSURL *url = [[NSBundle mainBundle] URLForResource:videoName withExtension:@"MP4"];
+AVAsset *asset = [AVAsset assetWithURL:url];
+AVPlayerItem * item = [[AVPlayerItem alloc] initWithAsset:asset];
+[self.pipController.playerLayer.player replaceCurrentItemWithPlayerItem:item];
+```
 
 
 # Demos:
@@ -27,6 +47,6 @@
 
 # Contact:
 
-For more technical exchange you can add my WeChat: *cq1351675135* or scan:
+For more technical exchange you can scan to add my WeChat:
 
 ![contact](contact.PNG)