Hi!
The APK version is currently only available for the full version of the game on Patreon.
This said the web game DEMO on itch can run on your phone's browser. I tried it on Chrome and it works just fine!
Once we release the full game for sale, we might make an APK version of the DEMO too for anyone who wants it. But right now it just takes time better spent on something else, when you consider that the DEMO works on browsers.