What is the best iOS app for editing a vertical video?

Quite simple to use and has bunch of cool feature: Video Montage Enhance your video with stickers Cinematic filters Ultra wide picture

Quik is by far my most favourite video editor because of its simplicity

If you want to create a slideshow, Remake is the best!!

Infinite Stories has a lot of video esiting features and many more coming in the following weeks!

I use iMovie for iPad and Joyoshare Media Cutter for laptops. Both of them have powerful features, more than I can list. But it will take some time to figure out how to use iMovie. Joyoshare is much more easy-to-use.