Fair Share is my first iPhone app. It is currently undergoing review by Apple.
Fair Share is yet another tip calculator. In fact, the working name was yaTipCalc. But Fair Share also does bill splitting which not very many of the tip calculators out there bother to do.
Hopefully it will be approved in the next few days. In the meantime, here's a demonstration of how Fair Share works.
I already have a number of improvements in mind including Address Book integration. If you have any comments, feel free to contact me at firstname.lastname@example.org.