Sprite Master application is a sprite sheet generation tool for mac. It generates your sprite sheet with powerful algorithms and generates smallest sprite sheet. Also, it exports coordinate data for you to use in cocos2d projects or other different format (like css, etc).
You can take a look at http://www.mobinodo.com/spritemaster for more information. If you need any additional information about Sprite Master, you can always contact me.
Yes, definitely. It just cheaper. Its all features not implemented yet we are updating it. You can see the features which we will implement at our FAQ page.
Every update will be free. You can also take a look at Videos page to see how it works.