This should work anywhere https://wiki.debian.org/AndroidTools is available.

The build is setup to work in place after NetRexx is installed and working.

You only need your favorite text editor.

It was tested with NetRexx-4.03-GA on Devuan Chimaera 4.0, using
openjdk version 11.0.16 and a D2-927G_BK Android 4.1 Jelly Bean tablet.

You must run make on the Makefile first to create keystore.jks.

Next you type "ant" to build the signed Android Application.

You can copy/rename this entire directory as a template, relocate your keystore,
use a different NetRexxR.jar or another Android platform version.

Just remember to change those variables in build.xml.
