Atro is a beautiful mobile UI kit that includes 12 ready-made screens you can start from for building your own app.
Freebies tagged mobiles
Slideout.js is a lightweight and dependency-free plugin for creating touch slide navigation menu for web and mobile apps.
Slideout.js – Touch navigation menu
Ionic is a beautiful front-end framework for developing hybrid mobile apps in HTML5. Available on Github.
Ionic – HTML5 mobile app framework
Today ‘s freebieis an excellent PSD UI kit. Crystal is a free Mobile Application UI design from cssauthor.com, you can use this in many ways
Crystal – Mobile UI Design
Download the high resolution free PSD mockup and resources of the newest Samsung Galaxy S III.
Samsung Galaxy S III PSD mockup
Another iPhone 5 free PSD mockup! Thanks to Roy Abbink.