BetterSnapTool

BetterSnapTool allows you to easily manage your window positions and sizes by either dragging them to one of the screen's corners or to the top, left or right side of the screen. This enables you to easily maximize your windows, position them side by side or even resize them to quarters of the screen. If you need even more than those standard snap areas, BetterSnapTool now allows you to create your own, custom snap areas anywhere on your display.

Other features include: custom keyboard shortcuts, customizing clicks on window buttons, moving/resizing windows by holding a key and many more.