Whiteboard is a power tool to help people sketch on phones, to demonstrating your ideas, keeping temporary notes, teaching your kids, etc.
1. four color markers, eraser with many line width.
2. unlimited undo/redo, clear whiteboard.
3. shake to clear
4. volumn down key = undo, volumn up key = redo
5. always screen on and sound effect setting.
6. save whiteboard as jpeg or png image.