I have a (recently jailbroken) iPad 3 on 6.1 and when I tried to buy "Little Inferno" in the app store today it wouldn't let me, I just got a popup:
This App is Incompatible With This iPad
This app requires a front facing camera.
I found another app which needed a front camera, and got the same issue when I tried it.
I have a a friend with a jailbroken iPad 3 and he is able to buy the app with no problems.
I've just tried selecting the front camera in the camera app and it doesn't seem to work any more (haven't tried it for ages but it used to). I wonder if something went a bit awry with my jailbreak. Anyone else experienced anything like this?