The 1.2.1 version of EdgeCase for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This Mac app was originally created by Peter Kamb. We recommend checking the downloaded files with any free antivirus. The software is categorized as Productivity Tools.
From the developer:
EdgeCase improves your multiple monitor productivity by restricting your mouse cursor to a single screen. The app prevents you from ever accidentally losing your cursor into a rarely-used secondary display, or from overshooting as you flick to an OS X hotcorner or the menu bar. When you do want to switch to another screen, EdgeCase provides several shortcuts that allow you to cross screen edges manually.
You may want to check out more Mac applications, such as pdf-DocPro, Simply Notes or Pads X, which might be related to EdgeCase.