The screen still goes off before the time is up
Almost always the phone closed the app in the background. Xiaomi, Oppo, Vivo, Huawei
and Samsung each have their own rule — autostart, sleeping apps, adaptive battery —
and the app names yours on its own screen. Excluding Screen Awake from battery
optimisation is what fixes it. If you have already done that, tell me the phone and
the Android version.
The tile is not in my quick settings
Android never adds it for you. On Android 13 and up the app has a button that asks
the system to add it; below that, and on some Samsung shades, you add it by hand from
the pencil or the edit button at the bottom of the panel, where the unused tiles are.
You would rather not grant the overlay permission
You are testing it and the screen never goes off
Check «Stay awake» in the developer options: while it is on and the phone is
charging, the screen stays on by itself and nothing you observe means anything. It
caught me out too.
You bought Pro and it is not unlocked
The app reads your purchases again every time you reopen it: close it and open it
again, with the Play Store signed in to the same Google account you bought with. The
same holds after reinstalling or on another phone. If you paid with a method that
takes time, such as cash at a shop, the unlock arrives when the payment completes.