This app was mentioned in 4 comments, with an average of 2.75 upvotes
I think that the Whatsapp camera is just the KitKat Camera.
https://play.google.com/store/apps/details?id=com.moblynx.camerakk
But I really hate Whatsapp's camera... If I take a picture while in focus, the result will be a blurry image, and the opposite is also correct.
I've been using temasek's and arter97's CM12 build for my S3 for 3 weeks now and it works pretty good. I wonder if there are other dev-supported Lollipop based ROMs for the S3 with the same polish and support that temasek and arter97 provide. Not necessarilly CM12, but something with the same speed and degree of modification, or even faster like Slimrom (never used it though so I don't know how fast it actually is).
To be precize, I'm curious if there are roms with: