I agree. Don't know what commercial plans you had for it, but I'd love to see something exactly like this as an open source single-page JS app that I could run as file:.. (this would help w/ pull reqs too).
For now I'm going to keep developing it as much as I can. I don't have any commercial plans. I thought about open sourcing it, and it's something I'm seriously considering.
I do plan to host it for a while, but if for whatever reason I were to stop supporting it I would make this clear very far in advance. I should probably talk about this somewhere on the website. I'm sure other people have the same question.
If you or anyone else has any other feedback/suggestions, please send it my way! My email is on the "info" page of the site. Thanks again.