We (Streak, YCS11) have been using this API for a few days to build our email snoozing feature ( https://www.streak.com/email-snooze-in-gmail ). The API is really nice to use and makes interacting with Gmail way easier relative to IMAP. I'm surprised they don't recommend using this API to build full email clients. I fully expected that to be one of the core use cases. The reason its hard (currently) to build a mail c…
If anyone wants to snooze email without auth'ing your Gmail account, here's one I built in 2008 that's still going strong. http://hitmelater.com/ It costs $30/yr for the high-end service but send me a note and I'll give you a link to signup for free.
Plus our snoozing functionality is 100% free, no matter how many you schedule, or how long it's for :)
Oh, and you can see/edit/manage your snoozed emails all from right within Gmail.
And we also have the "Awaiting Reply" view that doesn't require you actually DO anything, other than send out emails. We show you a custom list of the last 20 emails you've sent that don't yet have a reply.
edit: added more about what features we have