Hey VV,
To update the game, drop the latest .rpa in where you installed the game initially ("game" folder) and delete the old .rpa.
You don't need to download the launcher again.
Is this the way to do it on mobile versions? I just don't know how to find the necessary folders on android in this case.
Correct. We have an Android guide here if this helps:
https://rift.ink/3PADL3p
thanks