MatchCut (iOS|Android) is a fun app that turns your regular videos into a 30-second movie with background music that matches up with the action onscreen. It also has a social networking component where you can post your movies, see what others have posted, and "Like" what you see.
When I first watched a movie made from my video clips using MatchCut, it immediately reminded me of making "movie trailers" using Apple's iMovie app. While MatchCut doesn't have the same feature set, it's incredibly easy to use, but I still think it needs something more to really catch on.
Dive right in
Setting up a MatchCut couldn't be easier. Simply touch the Create button in the bottom center, then use tabs at the top to choose either from your portrait or landscape shot video clips in your smartphone's library. Touch to select as many of your video clips as you want, but remember you only have 30 seconds of show time, so three or four clips is probably about right. When you're finished with your selections, you can hit the Next button in the top right.
Your next step is to add some music. MatchCut comes with over 50 royalty-free songs for your MatchCut videos, with Hollywood-style themes (for that movie trailer feel) and several other indie selections that closely resemble popular music you probably already know. As an example there's a track called Gum Gum Style that closely resembles Psy's "Gangnam Style." There are selections for just about every mood so it's easy to find something to match up with your clips.
Once you've selected your music and hit next, MatchCut goes to work splitting up your clips and matching the cuts to the beat of the music. One thing that's great about the app is the process is extremely fast, letting you watch your preview in under 10 seconds.
Sharing your work
You can share your finished videos or just export them to your smartphone's library. There are not a lot of choices for social networks besides Facebook, but as the app description points out, it's very easy to post to YouTube and share with everyone.