Especially with the iPad App, using the touchscreen for annotating can sometimes lead to accidental highlights. In the case where this highlight is close enough to others, it's impossible to delete this mistake without deleting all the highlights in that group -- in which case, it's necessary to go back and highlight it all again.
Undo (and Redo?) button(s) would be great.
Hi, we have implemented the Undo button on the web and new desktop applications.
We are continuing to work on the Redo button and will notify you when it is added.
This would be a great feature to add and its the simple things like this that make the user experience fluid. Good suggestion, Christian.