For the purposes of a mash-up, I would recommend Popcorn Maker but both sites provide good resources. Below are the pluses and minuses of both.
Mozilla Popcorn Maker
- You can pull from YouTube. What kid isn't using YouTube?! No need for them to circumvent the system by installing shady downloading software. They also support Vimeo too.
- You can pull songs from Sound Cloud, meaning that students don't have to own the songs, and goodness knows they don't buy songs!
- You can either paste in the link to one of the supported media sites or search and Popcorn Maker will find results across the sites.
- Editing is relatively easy. My favorite feature is the audio on/off and video on/off buttons that make it so easy to lay sound over video.
- Sharing is easy! There is a link provided as well as an embed code. You can also share out over Twitter and Google+.
- AND, you can sort of collaborate. This means you can invite someone to look at your project and chat with you about it. That seems like a worthy feature to me!
- The layers can pile up and it can be really difficult to see how everything is matching up.
- Editing in WeVideo is A LOT more intuitive than iMovie and other programs.
- There are tons of quick tutorials that are easy to access and follow. Check out their academy.
- As a teacher or administrator, you can set up classes so that you can view student work. There are other educational features as well.
- It's expensive. Think $250 a year for 50 users.
- You can't collaborate like you can on a Google Doc. When one person edits the project, it makes a copy of the project. This means you will have multiple copies of the project and it's up to students to make certain that they are working on the most updated version.
- All imported content needs to be owned by the user and many middle school students own no content.
Overall, I would recommend WeVideo if you are working with original content and if your school has the financial means to support these accounts. But as you can see, I'm a fan of Popcorn Maker.