Seconding sbridge's post, us Windows users need either:
a) An app version, not in a brower, or
b) A functional freehand annotating tool in speed grader that works in a browser. The current one simply does not work. Every time you make a mark, a box comes up with a save/delete option, making it *impossible* (not difficult, impossible) to write. The "workaround" is to hold down a the mouseclick button on the pen, which means that the pen cannot be lifted.
I'm using a Wacom One tablet. Again, the problem is not that the freehand annotation too in the web broswer simply doesn't work as well on on an iPad. It is that it utterly unusable.