rozPierog

It's a per app thing. Developers need to support it sadly it causes some issues with layout that most developers don't want to deal with, so it's not that popular. It's especially an issue in the multiplatform apps that share codebase with iOS

You can also search for "One handed mode" in the system settings ,lthat will pull down the notification shade when you swipe down on the gesture pill

Good job on releasing your project to the public! Making FOSS because you are frustrated/horrified with permissions of the existing apps is something that I can truly relate to.