Check out [Web Applications][1]. Plenty of [Gmail questions][2] there. 

Note that if you have a question about Gmail interfacing with your computer, e.g. connecting via IMAP, or some browser extensions, that'd be on-topic for Super User.


  [1]: https://webapps.stackexchange.com/
  [2]: https://webapps.stackexchange.com/questions/tagged/gmail