How they heck did they do this? Custom number pad.

Question

http://itunes.apple.com/us/app/bistromath/id309214622?mt=8

Number pad in second screenshot:

So is this some customization of the stock keypad? Modal view?

Answer 1

Yes, it's a customized view including UIButtons

Answer 2

Customizing the keyboard is still completely unsupported, so it must be a custom view.