This is a great tool that I use almost daily with my students. It really makes it simple to show students something in particular on the screen. I use it most to highlight and follow my cursor as I show them webpages. It really makes it easy for them to focus in on what I am trying to show them. As a free tool it is hard to beat. It says that works with up to 10.6.8 but I have it working on 10.7 just fine. It has 11 different modes, but I use the Flashlight mode the most since it is the most simple and easy to use. It has lots of customizations to offer as well. Omnidazzle was once a paid piece of software but Omni is now giving it away for free. I encourage you to give it a try. Also if you have any suggestions for similar software that is free for Windows please let me know in the comments.