This Kickstarter looks very interesting : http://www.kickstarter.com/projects/539087245/spriter
In Short :
Spriter is a powerful animation tool for creating highly detailed 2d real-time game characters and effects in an intuitive, visual editor. The characters are saved to a format that allows game engines to produce higher quality visuals, while also using less video ram, and requiring less disk space per frame than traditional 2d sprite animation.
Spriter also provides several game specific features like collision boxes, and sound effect triggering, and saves to an open format that will be useable across many different game engines and platforms.
Intro :
http://www.youtube.com/watch?v=Pfhlsfc-EDM&list=UUCEtaUnreDcWsSCK_eicsqA&index=18&feature=plcp
Capability:
http://www.youtube.com/watch?v=9qUIwsHZUE8&list=UUCEtaUnreDcWsSCK_eicsqA&index=2&feature=plcp
Currently they have plugin for 4 game engines, Construct, Construct 2, Torque and Unity 3D.