Sorry for the delay. This is my first released project, therefore it was very nerve-wrecking putting it online. I'm still waiting for someone to rip apart my code, and call me a dumbass.
About texture packing, i think you've misunderstood the purpose of the project. I could even go about writing something to pack the sprites together later, but the main goal was to do the opposite, unpacking them. Why? Because there are many sprite sheets out there without any clear pattern so using them would be extremely painful, and cutting them manually is just not worth the time-investment. With this program, you can remove the sprites into separate files so you can handle them better. I also intend to implement a button to generate a json/xml so that you may still use the sprite sheet without splitting.
Sorry if I've no smart solution or anything, this is just my own implementation on the flood fill algorithm to figure out sprites' boundaries.