My son found this one tonight and rushed downstairs to let me know about it. From the Apple apps site:
REVITkeys is a list of 260 keyboard combinations for AutoDesk Revit Architecture 2010. Arranged in 14 categories for easy access this tool makes it easy to find the keyboard combination you are looking for or learn new ones. Utilizing REVITkeys for Revit Architecture will speed up your work and help you learn new skills.
Categories include: Project, Model Family Editor, Profile Family Editor, Truss Family Editor, Rebar Family Editor, Mass Family Editor, Conceptual Mass Editor, Detail Family Editor, Contextual Tab, Snap Overrides, View Control Bar, Context Menu, Navigation Bar, and Alternates with Closer Keys
It isn't free, nearly so...just 0.99 cents until it gets wildly popular. I didn't try it out myself yet because my phone is still downloading the latest update.