PhoneGap works too, especially considering you can target multiple mobile platforms at once.
Highly recommend phonegap. It's actually what im working/ learning on now, in correlation with cordova. Basically able to write apps for iOS, Android, Windows phone, and whatever else as long as you have the sdk files. Oh, and it only uses standard web languages (HTML, JS, CSS), which makes it super easy. Great if your in a hurry, or designing something that isn't very graphic intensive (games, simulations, etc.).