I started working on this app in April for personal use. I had a very bare bones version working while I was at Startup School.<p>My friend @coryschop asked a question about Twitter a couple of weeks ago, and I sent him a note showing this app to him, and he got very excited about it and told me he had to work on the design for it. :)<p>He's been using it for a few weeks now, the design looks a LOT better, and we just launched today!<p>Total amount I spent to "develop" this app: $55 (logo)<p>Even if you include hosting fees for a decent box on Rails Machine (i.e. several months of being tested by < 5 users) I've spent < $500 on it so far.