Here is a hard one: On all Apple devices only one GPU is used: PowerVR - and only one texture format for it - PVRTC On all Android devices many different GPU'

Here is a hard one: On all Apple devices only one GPU is used: PowerVR - and only one texture format for it - PVRTC On all Android devices many different GPU's are used, and you have to ship at least TWO different formats: one DXT-like (ETC?) and one PVRTC This can duplicate the size of your Android game compared to even PC.