Speed up for iPhone 5

I love this app but please add rewind and speed up for iPhone 5,5c,5s and any iPhone made after those. Alot of people cant afford an iphone6 so please take this into your consideration

I love the app but its impossible to edit a video longer than 2 minutes the app keeps crashing and then I have to start over it honestly makes me want to just give up and look for a better app...

Miriam034 about iMovie, v2.2.3