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By clicking on the image in the notes webapp, Ben brings up a pane that lets him add text labels to his diagram, and drag those around. The controls on the side of this pane allow you to insert labels, move them around, navigate around the diagram, and undo or redo actions.
Bringing up the app on your phone will pop a canvas into any notes that you have open even if you didn't click the drawing icon first.
Reviewing notes is less interesting than in our second design, since it is essentially the same as editing. You can browse through the navigation pane and locate notes by title, or use the search bar, which functions as in the previous two designs.