As someone who develops on PC I don’t have a lot of specific recommendations, and in general the best tools are exclusive to it. However, I think it might be possible to do some gamedev on mobile with gdevelop? The software can be used via a web browser and it supports exporting to android, so you might be able to try that. No guarantees, but it’ll cost you nothing to give it a shot.

If you have money you can try  Shadow, cost $30 but you have access to a computer

If you're willing to settle for interactive fiction, Borogrove is reported to work well enough on a phone, and for an offline app there's Fabularium. Sadly Twine isn't really usable even on tablets, if I remember correctly.

Edit: for a mobile app to export APKs is a tricky proposition. Google intentionally makes it hard through licensing and technical means. But I think Termux might include a way to do that. I haven't actually tried.