This might be an exaggeration but I have found Snagit by Techsmith to be a great productivity tool. Sure, there is a free one built in Windows, but it doesn’t have any of the great markup features that Snagit has. Working on plans and need to send a markup? Just press the printscreen button and Snagit starts up and enters into a screen where you can annotate the screen shot. I use this software all the time. It also has a great feature in pasting the finished screen shot directly into your email. Go to this LINK