This is really fantastic, great job. This is exactly the type of stuff we love seeing built and used with Mailgun.

Regarding analytics, we do provide detailed data either in push (webhooks [1]) or pull (campaigns api [2]). Did you just not have time to integrate that or is there something else that we could have offered to make it easer for you?

[1] http://documentation.mailgun.net/user_manual.html#events-web... [2] http://documentation.mailgun.net/api-campaigns.html