MacroCycloWhat's a great buy it once Android app?
Tasker. Basically an interface for writing scripts for your phone. Even if you don’t have a use case in the beginning you’ll start finding things to do with it.
What are some things you use it for if you don’t mind my asking?
The main thing is a script to stop any media playing and turn off the screen after x minutes, so I can fall asleep watching YouTube or listening to something. There’s probably already an app for that but this is pretty customizable.
Another stupid use is putting the phone on silent while using the camera app because Samsung won’t let you turn off the camera shutter sound.