The Clinton campaign app that helped win the Iowa caucus

I helped with some of the UI for the boiler room in 2008. This article only touches on the GOTV and targeting aspects although the most exciting component would have been the ability to allocate human resources to contest improbable results in real time.

Off the top of my head: I don't think there's a good solution to verify ad-buys in small markets. You could make a pretty penny sticking a webcam in front of an over-the-air broadcast TV in every county in every swing state and hiring someone to tick a box every time a candidate's ad plays.