PiP for Mac - Always on top window preview similar to the popular windows only OnTopReplica
Virtual Magnifying Glass - Virtual Magnifying Glass, a free, open source, screen magnification program for Windows, Linux, FreeBSD and Mac OS X. Free full version download and instructions for use.
PiPer - A DIY Minecraft computer to build gadgets
Magnifixer - Magnifixer is a screen magnifier utility.
CThruView Transparent Image Viewer - CThruView is a free transparent image viewer that allows mouse clicks to go through the image.
ZoomIt - Presentation utility for zooming and drawing on the screen.