Scrapbox - A new style of note-taking that lets you create, discuss, and learn together in one self-organizing space.
Limnu - Sketch, share and collaborate with your team
Penbook - The nicest freehand writing app ✍️
Draw.Chat - Anonymous real-time whiteboard with text and video chat.
OneNote - Get the OneNote app for free on your tablet, phone, and computer, so you can capture your ideas and to-do lists in one place wherever you are. Or try OneNote with Office for free.
Sketchboard.io - Visual Remote Teamwork. Solve problems and create ideas on endless whiteboard with your teammates by sketching.