What apps are people using to markup PDFs with the Pro's pen? I'm a teacher and use PDFs a lot in class. I have been using PDF Xchange for years to type on, and draw lines and circles on PDFs in class. With the SP I'd like to be able to write on them using the pen. I've tried using the pen tool to write in PDF Xchange and also Nitro. Both are not very good for inking. The 2 main problems are: 1. What I write doesn't appear anywhere near as smooth as it does in One Note. 2. I can't write/draw a dot. Both programs require a certain length of pen stroke before registering any marks on the screen. So, I can't use any periods, or dot my "i" and "j". Is there a PDF app that lets you ink as good as One Note? Thanks, Rich.