Very cool. Some initial impressions:

- There is no indication that you need to verify your email until you do a disallowed operation, it would be nice to indicate this so that I go do that before starting using the app only to hit a wall because I haven't verified my email.

- The result of verifying your email is just plain text, it would nice to at least have a link back to the app's UI.

- No content from the feeds is displayed. This is complex for security and formatting reasons but it would be nice. But some people like just titles.

- WebSub support would be nice.

Overall quite pleasant. Nice work!