Below is the full source code for the NodeCore engine fork, as required by the LGPLv2.1 license to provide the source code of forks. It is provided as-is, with all the source code included that made the binary build available on Google Play.

Download me! (2023-02-23)

By the way, the NodeCore engine fork is based off of ROllertest. Also see the Distributing Minetest Games page on the Voxelmanip Wiki if you'd want some details on how to distribute Minetest games independently using an engine fork.