iOS: If you frequently shoot videos on your iPhone, you should download Fly.
These four videos are laid out in a grid below the preview.
you’re free to mute any videos or add voiceovers too.
With in-app purchases, you might unlock features like music, picture-in-picture, dissolve transitions, and split screen.
Get them all with the $5.99 pro pack, or pay $2.99 for individual packs.
One problem is that Fly works only with widescreen/landscape videos.
Fly (Free)| iTunes App Store viaApp Advice