I made my first android app today. It was terrible and I plan to never do it again.
It took me about three hours of trying to get the sample apps to run before I gave up and made something from scratch. Both involved heavy use of ChatGPT (not my usual flow).
That said, if you want an app that reminds you how to tie your tie in an easy step-by-step way, you can download the APK from my website, and I believe you should be able to run that on your phone.
I don't know how to easily share Android source code, so I won't.