This is a minimal Scala app that runs everywhere if you have a JVM with Java 17 or higher installed.

It prints "Hello world!" in terminal using this Scala program:

@main def run = println("Hello world!")

Run using the java command:

java -jar hi.jar

Or if the jar is made executable with chmod +x hi.jar on linux:

./hi.jar

Or if you have scala-cli installed:

scala-cli run hi.scala

If you have scala-cli installed:

scala-cli --power package helloworld.scala -o helloworld.jar --assembly`

1. Install F-Droid from here: https://f-droid.org/
   (you need to allow your browser to install unknown apps)

2. Search from inside F-droid for "Termux Terminal emulator with packages" and install it by pressing the down-arrow in F-Droid (you need to allow F-droid to install unknown apps)

3. Open Termux and type this by the $ prompt:

   pkg update
   pkg upgrade
   pkg install openjdk-17
   pkg install wget
   wget https://github.com/bjornregnell/hi/releases/download/v1/hi.jar
   chmod +x hi.jar
   ./hi.jar
   

Con gratulations!! You now know how to run your own Scala terminal apps on your Android phone!

It is pretty cool: