Cinch

Cinch screenshots

This Mac program helps you resize windows on your desktop.
Cinch 1.2 : Cinch Setup Window

Alternative downloads

SizeUp
1.7.4
This application helps you easily resize and position windows on your screen.
Arrange
3.2
Best solution to control position and size of applications'
MaxSnap
1.74
Move, arrange, and resize windows with a menu-bar icon or keyboard shortcuts.