Using Echoprint technology, I made a system to listen to what movie is playing and then automatically synchronize my Rifftrax audio files to the movie. This was my entry into AngelHack Seattle Spring 2014
AngelHack SEA 2014
There are a few parts to this system. First, I took a couple movie files and ran them through Echoprint-codegen, and stored that in an Amazon RDS instance. I used node-echoprint-server and modified it to include rifftrax-specific synchronizing information. Then, I modified the echoprint-ios-sample app to play the proper rifftrax file at the correct time.

If you can't tell, the phrase "...every couch cushion." was the app's addition to the movie.

I'm really excited about this technology, and I plan to keep working on this product until it's ready for production. There are many ways to improve this technology for this particular use case.