Wow, seriously cool. I like it. Simple and good looking. Plus, you added a Heroku deploy button to the GitHub project.

I was able to setup at https://manuisfunny-test-prelaunch.herokuapp.com/

It took like 10 minutes to get it up and running. Most of that was getting signed up with mailgun (I'm kinda slow, used the wrong api key, so the average developer might get it done in like 2-4 mins).

Thank you for this app.