SkiTips Before you hit the slopes, make sure you know what you're doing. SkiTips offers instruction for different ability levels. Whether you're still learning to snow plow or you're a regular on black diamonds, SkiTips provides helpful video tutorials. If you're a green circle skier and you find yourself on a blue, you'll be glad you learned how to side slip your way down. Or break "bad habits," with the instructions on improving your stance and turns. Most importantly, learn how to stay in control. After mastering the lessons on this app, you'll be headed down the back bowls at Vail in no time! The free app is compatible with iPhone, iPod touch, and iPad, but requires iOS 3.1.3 or later. It is also available for Google's ( GOOG) Android operating system.