RubyMotion is a revolutionary toolchain for iOS and OS X development using the Ruby programming language. With RubyMotion, Ruby developers can finally write full-fledged native apps for iPhone, iPad and Mac. RubyMotion apps are fully compiled into machine code and perform as fast as apps written in Objective-C.
There are lots of apps written in RubyMotion. Popular ones include 37signal's Basecamp, Frontback, Jukely and Bandcamp.