iOS Design Kit - The newest library of native iOS templates
UserTesting.com - Usability testing has never been easier. Get videos of real people speaking their thoughts as they use websites, mobile apps, prototypes and more!
iOS Design Course - The Complete iOS Design Course with Sketch from Bitfountain
Userbrain - Easy, fast, and affordable user testing for websites and prototypes.
Xcode - Xcode is Apple’s powerful integrated development environment for creating great apps for Mac, iPhone, and iPad. Xcode 4 includes the Xcode IDE, instruments, iOS Simulator, and the latest Mac OS X and iOS SDKs.
userinput.io - Get on-demand feedback for your app, website or idea. Learn how to improve by hearing real opinions.