ReelDirector [iTunes link] has updated the popular iPhone editor to version 2. The U.S. $7.99 app from Nexvio now allows you to do multi-track sound editing and mixing, use stills in addition to video and do a Ken Burns effect. You can also trim and split imported clips. Owners of the older version can update to version 2 for free.
Other features include the ability to change the length of opening and closing titles, and automatic flip of clips that came in upside down.
I kind of marvel that you can do this all in a phone, but you can and it works pretty well. When you are done you can email your finished video (there are limits to the size of videos you can mail) or just put in in your camera roll and export it later.
There are still some weaknesses to the app. The biggest is an inability to use iTunes music for background sound. Apple does not allow this on the iPhone, but they do allow it in iMovie on the Mac. Go figure. You can record sounds live of course, and always hold the iPhone up to a speaker to get some music, but that is a pretty low-tech way to get that done. The Ken Burns effect is limited to one simple zoom-in. You also can't title projects in the middle, only at the beginning and the end. Documentation is pretty slim, and the linked video of instructions is for version 1, not version 2.
Having said all that, ReelDirector is a remarkable app. No, it's not Final Cut Pro, but it runs on a dang phone! The developers are very responsive to customer suggestions, and this update added a lot of asked-for features. If you want to get those pictures of Uncle George eating his turkey dinner edited and sent out before dessert is served -- and without leaving the table -- you can do it.
What a world.