Spriter is a 2D sprite animation tool that runs on Windows, Mac, and Linux. More info here:
Spriter Homepage
Unfortunately there isnt an official cocos2dx loader. There is an older loader that maybe could be a starting point to create a new one:
Older loader for cocos2dx
Also there are C++ and Javascript API’s so you could create loaders from that hopefully:
Spriter APIs (scroll down a little)
Pyxel runs on Windows and Mac and is an editor for tilesets. More info here:
Pyxel Homepage
You can pick both up for $1 as part of the latest Humble Bundle here:
Humble Game Development Software Bundle
I havent used Spriter or Pyxel and have no connection to the developers - but this looked like something fellow cocos2dx developers would be interested in.
thanks, Codemattic