From Phys.org:
• Transform your video with the new green screen effect that lets you instantly remove the background of clips shot in front of a green or blue screen
• Adjust the green screen effect with a 4-point mask and strength slider
• Choose from 80 new soundtracks in genres including pop, chill, and sentimental that automatically adjust to match the length of your movie
•Drop in still images with transparent backgrounds to use as logos or custom graphics on top of your video
• Add photos as overlays to create picture-in-picture and split-screen effects
• Choose to hide the border that surrounds picture-in-picture and split-screen effects
• Instantly return to the edit screen of your project when switching back to iMovie from other applications
• ClassKit support lets students deliver video assignments to teachers using the Schoolwork app
• For users with videos in iMovie Theater, the Theater window is now accessible from the ••• menu at the bottom of the Projects screen
• Sharing to iMovie Theater is no longer supported; save your movies and trailers to iCloud Photos to watch them on other devices including Apple TV
• Resolves an issue that could lead to a black viewer when previewing your video fullscreen on an external display.
