Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Limnu - Sketch, share and collaborate with your team
Paste by FiftyThree - Show your work. Paste is a new presentation tool for Slack.
Draw.Chat - Anonymous real-time whiteboard with text and video chat.
Inspect by InVision - A magical new design to development workflow from InVision
Sketchboard.io - Visual Remote Teamwork. Solve problems and create ideas on endless whiteboard with your teammates by sketching.