Flockdraw - website states, "is a free to use online whiteboard based painting & drawing tool. It makes it easy to draw online free with multiple people for fun or business. You can have unlimited people in a room and the drawing updates in real time. Uses different colors, shapes and text."
Educreations is a global community where anyone can teach what they know and learn what they don't. They are on a mission to democratize learning by extending the reach of great teaching. This is totally what we are all about!!!!!
Host and Document Collaborative Brainstorming Sessions With Realtime Board - The service allows you to work with any information and visual content on one board individually or with a team. You can work with images, videos, PDF-files, write notes and comment everything, use colorful post-it stickers and files from your Google Drive. The free education version allows you to create unlimited private and public boards, have an unlimited number of collaborators, and 3GB of storage space.
CoSketch is a collaborative drawing site which requires no joining, logging in or registration. Perfect for elementary classes. It’s a no frills tool, so there are not a lot of extras, but for simple drawing and text, it works great. Users just go to the site, click on create a sketch, and begin drawing. To add more people, you just send them the url.