Screen Resolution Manager - Screen Resolution Manager is one of the robust and streamlined desktop applications that come with an easy way to adjust your screen resolution.
DisplayFusion - DisplayFusion will make your multi-monitor life much easier.
EasyRes - EasyRes is a fast screen resolution switcher for Mac OS X with live animated previews.
WindowGrid - Quickly and easily layout windows on a dynamic grid using just the mouse.
HRC – Hotkey Resolution Changer - If you are looking for a sumptuous desktop application that will overcome every bit of your need to adjust the brightness, resolution, and color contrast of your screen, then Hotkey Resolution Changer can be a smart option for you.
Mizage Divvy - Divvy is an entirely new way of managing your workspace.