Weavly. At that time it was brand new. A few months have passed since then and Weavly has improved. Weavly still provides a simple drag and drop interface that allows you to search for, trim and combine tracks without ever leaving the Weavly site. You can mix together video and audio from YouTube, Vine, and SoundCloud. You can also add animated GIFs from Loopcam, Tumblr, and Imgur.
The first of Weavly's two big improvements is the addition of an education section that offers excellent video project ideas. The other excellent improvement is the option to register for the service without using a social media profile.
To start creating your Weavly video perform a search for video content. When you find a video clip that you like drag it to the Weavly editor where you can adjust the start and end times of the clip. Then move on to adding sounds by search for sounds and draggin them to the Weavly editor where you can again trim the start and end times. Finally, you can add some animated GIFs by searching for them and dragging them into the editor. You can repeat all of these steps as many times as you like to create your video.
Applications for Education
One of the suggestions from the Weavly teacher page is to have students create anti-bullying videos. Another possible use is to have students create short weekly news summaries by mixing together news clips from YouTube.