Indigo Studio »

An interaction design tool that helps you “create functional, animated UI prototypes while maintaining the focus on user experience at every step”

PlaceIt »

This is awesome. Drag and drop an image into the browser to “generate product screenshots in realistic environments”.

Remote Preview »

A tool that “allows you to preview any URL on large number of mobile devices simultaneously. Just enter a URL, hit enter, and new URL gets automatically loaded on each device. Remote preview works on platforms like Android, Blackberry, iOS, Maemo, Meego, Symbian, Windows Phone and WebOS.”