Emulsio (free, but more about that later) takes a shaky video and really smooths it out. Shoot a video of up to 15 minutes in length with your iPhone, iPod touch or iPad and load it into Emulsio. The app fixes horizontal or vertical movement, and even removes some shots that are just too shaky for viewing. One nice feature of the app is that you can see a split screen of the processed and unprocessed video, allowing you to increase the strength of the stabilization routines to fit your needs.
You can then send the photo to your camera roll, email, Facebook, Dropbox, Evernote or iMovie. The processing was very fast on my iPhone 5s -- a twenty second clip was processed in about eight seconds, and it was obviously smoother and more professional looking. You can see a good demo video on the web.
Emulsio video stabilizer for iOS
OK, on to some complaints. While billed as free, the app is just a sampler for the "real" US$1.99 version which is available as an in-app purchase. The free version processes only 30 seconds of video, and then exports the processed video with a watermark -- that makes the app pretty unusable in the real world. I think free apps should not be so completely encumbered. Frankly, Emulsion is worth $1.99. It does what it does very well, and in my view it should be sold that way. Sure, the app will get sampled for free, but I think happiness will be followed by disappointment at how crippled the free app is.
A lot of work went into producing this app, so don't let my negative comments about the free app dissuade you. Emulsio supports most Apple hardware (iPhone 4 and up, iPod touch 5th generation, iPad 2 and up) and it is optimized for iOS 7 and 64-bit devices.
Emulsio really does work. I just dislike the come-on.