Help us out - what is Spine? If it is an animation tool, just make sure it exports PNGs as individual sprites. Then you bring groups of sprites into Buildbox for character, object, enemy, platform, powerup/action, decoration and so on
http://esotericsoftware.com/ Spine is an animation suite designed to help speed up production (aka animate 1 to 3 drawings vs 10sprite sheet animation builds) I think I have seen peeps on here say they have used it, but would love confirmation before committing to using it to save time/money. @Andy if you could confirm this I would greatly appreciate it.
We don't at this time support Spine or any bone animation in game play. It's on the radar for sure... but it probably won't be this year.
Spine or any other animation application (like After Effects or Spriter Pro) can export PNG which then can be used in Buildbox. More information here: http://es.esotericsoftware.com/spine-export#PNG It doesn't support JSON or Binary (http://es.esotericsoftware.com/spine-runtimes) because Buildbox has not integrated Spine Runtimes, but it doesn't mean you can't use the app to animate your cycles and use it with the PNG export option. I think BB2 even has video support so this would be another export option to consider.