SyncPad
syncpadapp.com
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
SyncPad is the ultimate whiteboard for remote and local collaboration. Would you like to share your ideas with a coworker but you are out of town? Don't worry, just create a room with your SyncPad and share the name of the room with your co-worker, who can enter in his SyncPad or simply use any browser, visiting http://mysyncpad.com/roomname.