A company called UIEvolution has managed to combine two things that we figured were implacable foes: Apple's iPhone and Microsoft's Xbox 360... on the iPhone.
Yes, it's a cheat guide. It apparently contains "all known and secret achievements with expanded information into the games, including game descriptions, videos, stats and the details that matter."
All known ones, for all games? We can't wait to see what Microsoft's publishing partners make of this.