Twiddla is a free, no-setup, web-based meeting playground. Mark up websites, graphics, and photos, or start brainstorming on a blank canvas. Voice and Text chat too!
Rather impressed by this tool. I like the idea that it is a truly collaborative board so you can edit other students work. Treating it like a Padlet means that students can move other students notes around.
The grid feature is an added bonus which allows you to position objects where you want. You can also import images and websites as “backgrounds”. Lots of very powerful tools.