Editing movies on an iPhone is going to be a horrible experience. Screen is too small and controls are limited. I'd probably stick to iMovie. Pinnacle Studio is not bad either, though I haven't tried the iPhone version.
For shooting, I've used Filmic Pro for a long time. Gives you some nice professional features. You can lock your focus and exposure, manually white balance, adjust resolution, frame rate, audio quality, recording format, has framing guides. Even does chroma key. Newer version has added some more features, but it's iOS 8 only. $8 on the app store.
http://www.filmicpro.com/