A very simple demo to how applications like CheatEngine, GameKiller, GameHacker... allow rooted android devices to cheat in games via memory manipulation.
The structure of the project is based on android studio so opening it as a project in android studio and building it should be a plug and play.
Building the app with apktool should also work but I didn't test it.
If you wish to edit the native C binaries and recompile them, make sure that you have NDK build tools that could be downloaded from here Once downloaded navigate to the jni directory and execute the ndk-build in the directory:
cd CheatEngineApp
cd native_bins/jni
$PATH_OF_NDK/ndk/android-ndk-<version>/ndk-build