http://www.playtwabble.com . It's a point system game based on the vocabulary you use in your status updates. Points are awarded like Scrabble.
I built it to learn Python and Django and also as a resume builder (I am looking for a software dev job...). I didn't build it to showcase my web design skills.
It uses Oauth to do sign in with Twitter, and because I know HN is weary my app requests write access but will only send a message to your stream if you explicitly tell it to.
The description on the home page doesn't make the game clear to me, and isn't compelling enough to make me want to hand over my twitter credentials.
After poking around a bit I found the "Most Active Games" box, but the pages those links take me to don't really have any more information, just a tag cloud of evidently broken links.
I spent maybe 3 or 5 minutes there, and I still have no idea what Twabble is or what it does.