I use the Schoology app on my iPad to grade student work submitted digitally. It is INSANE that there is a pen feature but no corresponding eraser. I know you can use "undo" but that is time consuming when you need to click it for each stroke, plus, if you have already written other things you have to undo all of that first before erasing the desired markings. Furthermore, if you've already saved your annotations, you cannot even "undo' them anymore. It looks bad when I have to scribble over things on a student's assignment just because I don't have an eraser. It's 2020 - an eraser should be commonplace in any annotation app!!!
Eraser needed in Schoology app for annotations