For those of you who used SIZEWELL with "Yosemite" and earlier OSX versions, it is not supported for El Capitan.
This application, BetterTouchTool (BTT), may work for you:http://www.bettertouchtool.net
There is a little bit of work setting it up to customize depending upon the ways in which you want your mouse and/or track pad and/or keyboard to function - ranging from a few simple actions (such as resizing windows with the mouse) to more involved shortcuts, etc. UPDATE: Actually, I discovered that SIZEWELL still works - although no longer supported - with (many/most) NON-APPLE apps such as Adobe Reader, Apache Open Office, etc. As expected, SIZEWELL does not work with El Capitan's Finder and Safari.