Splice is an alternative video editor(other than paid iMovie App) that you can use for free….See Details.

Splice lets you cut, clip, and edit your videos on your iPhone or iOS, You can add multiple video clips back to back, choose transitions, and select background music that comes with Splice (two tracks come free, but you can purchase more from within the app) or add something from your iPod’s music library. One Problem is the Free version comes with iAds, but If you don’t like ads while you’re editing, Splice can be purchased ad-free for $1.99—still quite a bit cheaper than iMovie’s $4.99 price tag.