This is a mod menu with ImGui for Android Unity Games Preview (built in Granny 3):

Later.

1. Copy your builded lib to lib/armeabi-v7a

2. Load the library on Activity Start. Tutorial:

   You need to add following lines in com/unity/player/UnityPlayerActivity:

const-string v0, "_ozMod"

 invoke-static {v0}, Ljava/lang/System;->loadLibrary(Ljava/lang/String;)V

Do it like that

1. This is the old project. If you really need to understand and build it, then do it by yourself, this project is no longer maintained.

OpenGL (GLESv2), EGL