Popplet (13, filtering, not searchable, middle, high)
Popplet allows users to create interactive graphic organizers and mind maps. Users can import images and YouTube videos (will need to carefully select these), annotate images, and add text. If you share a popplet, you will be given a random url that is public and can not be unshared. While this is fine for teacher use, I would not advise this option for students. Students can embed, export as a jpeg or pdf and print it. (This tool is also a free iPad app: Popplet Lite).
Here is an example highlighting technology tools:
Here are some screenshots of other activities that you can do: