itch.io

Then just backup the apk file or whatever you download.
Get a pc and download the android version and put it somewhere.
If you can't access a pc, get a usb storage device for your mobile, some come with backup features, so you can just choose the android version of the game and backup it.
Why do I have to explain it even, nobody explained anything to me nor needed.
I'm just wasting my time here.