Yesterday I've deployed the app and API to https://app.releaseflags.com!
Sign up is easy, since I'm using Auth0 you can either create an account or use Github to sign in.
So far, I'm not storing any personal data, not even an email address.
If you use it, be aware it's under active development and there is no certainty of uptime or even a stable database. I might have to redeploy the whole set up and have no ability (yet) to restore any of the data.
I've put up an open Trello board with my Roadmap, which is open for bugs reports/feature requests for any registered Trello user:
https://trello.com/b/XDLOC88r/releaseflags-open