CutStory is a video editing app for Instagram stories. It makes it easy to chop a longer video up into the required length for Instagram Stories (15 seconds maximum per clip). This way, you can repurpose longer videos—from your brand’s YouTube library, for example—and create more robust content without having to continually stop and start the camera.
A tool coming to the latest versions of video editing applications is support for seamless transitions. Picture a scene showing people at a beach, and suddenly the sky zooms in and your in Rome or Paris, but it looks like you're in the same place because the transition glued the two scenes together using the sky. There are plenty of other examples of seamless transition; this magnificent video shows a good selection of them, and is partly responsible for starting the trend.