Используйте приложение APKPure
Историческую версию UCS Theme BigThumbs можно получить на Android
Тема использовать в Ultimalte Call Screen HD
A theme to use in Ultimalte Call Screen HD, personalizing your fullscreen caller ID screen.
This app does not appear in your regular drawer, and does nothing by itself. To use, open Ultimate Call Screen HD preferences, go to Theme Manager and apply. Within Theme Manager you can also preview what an incoming call will look like.
Enjoy!