Dotstorming is a good tool for hosting online brainstorming sessions and or general gathering of ideas from an audience. I've featured it in some of my workshops over the last couple of years because it is quick and easy to get a lot of people using it at once. On Dotstorming you can have people submit ideas in the forms of text, image, and video links. All submissions appear in a grid where viewers can then vote and comment on the submissions. Recently, Dotstorming added a couple of new features that teachers will find helpful.
Dotstorming has always let users add images to their submissions, but now the process is a little easier than it was before. In the past you had to use a specific "add image" command to add an image. Now you can just paste the URL for an image into a submission and the image will appear.
The second new feature is the option to clear a board. Choosing to clear a board will remove all comments and votes that have appeared. The original submissions themselves stay on the board.
Applications for Education
The improved "add image" option should make it a little easier for students to include images in their submissions to a Dotstorming board. The "clear board" option will be useful to teachers who want to re-use the same board for multiple classes. The "clear board" option will also be useful if you want to have students vote at the beginning of a lesson and have them vote again at the end of the lesson.
Learn more about Dotstorming in this video that I made for new users.