It adds rounded corners to your screen.
This app offers many settings which allow you adjusting the corner's radius as well as specifying which corners to enable you to round.
Permissions
• System overlay - used for draw over apps
App is ad free, you have to pay only once.
Just download Roundify & give your screen a new look!
For any suggestion and bug mail me.
For Samsung device: To prevent the app stopped by itself:
System Settings > Device Maintenance > Battery > Unmonitored apps > Add apps > checked Rounded Corner
For XIAOMI smartphone: need manually grant "Draw over other apps" permission (Go to Setting > Installed apps > Rounded Corner > Permission manager > Display pop-up window > "Allow").