Starting out with Arduino or just need an offline Reference? Check out this app! Arduino Companion is an app for designed to help anyone getting into Arduino and electronics.
The app contains the full Arduino Reference for offline use, as well as a handy resistor calculator. The Reference contains all of the basic Arduino reference, but it also covers all the included classes for controlling Ethernet, Servos, Serial Communication, LCD Displays, SD cards, Keyboard and Mouse (Leonardo) and more.
Version 1.1 adds the two most requested features, but feel free to suggest features you feel is missing or would like added using the support page http://getsatisfaction.com/intopublish/products/intopublish_arduino_companion If you experience any problems, please leave a message there as well so I can fix the issue.