I built this library when our Storybook app launched and we needed a tutorial to walk users through the process of making a story book. With TutorialKit you can highlight important elements and wait for touch or gesture events to trigger completion of each step. You can also display a message for each step describing the action in detail.
Read enough? Grab it from cocoa pods: http://cocoapods.org/?q=tutorialkit
Alternately, you can view the source on Github: