Rifftrax - the first six Star Wars Rifftrax, free w/ Android App (iOS coming soon!)
From the app:
From the guys who brought you Mystery Science Theater 3000, RiffTrax makes movies FUNNY! Our hilarious commentaries turn some of the biggest blockbusters (and cheesiest B-movies) into comedy hits.
Using the app, you can download these "riffs" on blockbuster films like the first six Star Wars episodes! The app listens to the movie, using your device's microphone, and automatically synchronizes the commentary to play along with perfect timing. Presto! That movie is now a comedy smash.
Get into RiffTrax and start watching movies in a whole new way!
GPS location no longer a requirement!
(NOTE: This app is a demo version. You'll be able to connect your RiffTrax.com account in a future update.)
Not sure how long the free tracks are included, but I figured getting it now is paramount.