Transparent Red – CM13 Theme v4.1Requirements: 5.0 +Overview: Like a glass!! This is Transparent Red theme for CM13, CM12 (Cyanogenmod 12), CM12.1, CM11 and other custom roms with theme engine. 

Many apps of your rom will become transparent! You can choose a wallpaper and use it ... http://www.apkformod.com/transparent-red-cm13-theme-v4-1/