iMovie is great but pretty limited on the features when you want to add effects, texts and animations.
This is where Cute CUT shines. It's. fully featured video editor for iOS. The latest update, version 1.5, just made Cute CUT much better than iMovie.
Here's the link to download the trial version: Cute CUT
My latest video, Hot Coding! News was entirely done using GarageBand for the music and Cute CUT 1.5 for everything else...