"Big" is relative. The company I work for built this app for Sony Music. We're actually a fairly small company, around 30 employees, with about 20 of us being developers. We focus primarily on web apps built using Flex, and KC was our first iPhone app. But even though we have about 20 devs, the KC dev team was 3 guys, and 2 designers.
I'd love to give out some promo codes, and if they were mine to give, I would. But… Sony is in control of those. Maybe I can get my hands on one or two though. ;)
We tried a few different frameworks, before settling on Cocos2D, and we're already at work on our second app based on Cocos2D, so obviously Riq and the rest are doing something right.