SimonBlog recently updates its flagship Handbook app for iPhone with redesigned user interface The Handbook app takes users' iPhone knowledge to the next level. It covers all hidden tips and tricks including how you can create free iPhone ringtones, setup conditional call forward and improve battery life. 

User Reviews:
* 5 stars - Best!!!!!!! Very useful, one of the best out there for free. Good work, easy to understand with screen shots
* 5 stars - Excellent quick reference!! This app is a MUST for anyone who wants to have a basic reference tool that provides quick, easy reference and info about iPhone features. I am new to iPhone and found this app a lifesaver to get me started on learning about features and how to use them