"Most successful private project" would be an extension of the webeditor Brackets named brackets-swatcher.

The silly thing about this is that it started out from my own frustration with variablenames in variablefiles in Foundation and Bootstrap.

After a collegue of mine also used it he had a shitton of ideas how to improve and what he wants so i developed it on many weekends with many many beers in my belly.

Where we come to the conclusion - its for sure the ugliest project ive ever written (=> beer and jquery) and i hope i never have to touch the code again - but on the other side i never had bug reports despite the fact that alot of big websites had it in their "Top 10 Brackets Extensions" and many downloads from the Brackets Marketplace.