FollowUpThen was built to solve a problem we had while working together on other projects - not responding to each other's emails! We used it only internally for some time, making many improvements..and then decided there could be others with similar problems.
Finally gave this a try. I'm impressed. Very simple and I'm personally fascinated by "invisible" products designed to accomplish simple tasks with as little friction as possible. Reminds me of @msg's Super.cc.
Faster Than Normal: The Getting Up Early Episode
Product Hunt
Alert.email