I have a Surface Pro 4, and I'm looking for a simple PDF viewer that works well in tablet mode. I used to use Edge, but after they switched to chromium it lost a few key features for me (pen input automatically being a pen instead of scroll, pen eraser working, full screen page swipe rather than scroll, etc). Everything else I've found is either way overpowered and cluttered, or doesn't work well with tablet mode and pen input. Any suggestions?