We've developed various Steem-based applications, but we haven't released them for public use yet. The ones that come to mind off hand are a messaging system that allows chat/email over the Steem blockchain and an accounting system that can analyze Steem wallet transactions for tax purposes (but this is part of a much larger system). We also have a prototype vote bot that we've never really used.

This sounds exactly what me and @bsameep might have written !