iMovie for Macs goes 4K, lets you continue edits from iOS
 

Just in time for new 4K and 5K iMacs, Apple released a major update of iMovie for OS X that adds 4K video editing, along with a slew of other changes. The iOS version of iMovie got 4K support last month to coincide with the debut of the iPhone 6s....

http://www.engadget.com/2015/10/13/imovie-mac-4k/