Are you planning to make a plugin for sponge?

It's something I did consider a while back. Internally, sponge has a different way to do the NBT stuff, that would require many changes to the NBTEditor code. I did have plans to do a major overhaul of the NBTEditor, but never got around to it.

Right now, after a long time without properly updating the NBTEditor and even more time away from Minecraft, I'm not sure I have the time and willpower to do these major changes. Much less making it compatible with Sponge.

So for the time being, I'm not considering Sponge. Sorry.