[Q] Full screen caller or transparency to incall screen ? topic

I have always wanted a full screen incall screen or the transparency in the incall screen to get a full photo of the caller. have seen many ROM's implementing this feature on 4.3 and also on 4.4. Recently many devs have started removing this feature from their builds. Any way i could implement it in my phone ? Any flashable zips for this feature ? I am using Purity Rom currently.