AltDrag allows you to move and resize windows much easier. When you have it running you can simply hold down the Alt key and then use your mouse to drag any window, and it doesn't matter where in the window you click.
ShiftIt is an application for OSX that allows you to quickly manipulate window position and size using keyboard shortcuts. It intends to become a full featured window organizer for OSX. It is a complete rewrite of the original ShiftIt by Aravindkumar Rajendiran which is not...Discontinued
This project is looking for a new maintainer. Until that transition is completed, there will likely not be further development on this project.from https://github.com/fikovnik/ShiftIt/blob/master/README.md
KDE Mover-Sizer is a lightweight program enabling KDE-style alt-click moving and resizing for Windows XP, 7, 2000, 2003, Windows Server, and Vista.
Amethyst is a tiling window manager for Mac similar to the xmonad tiling window manager popular on Linux. Amethyst is written in Objective-C and has configurable shortcuts, multi-monitor support, multiple layouts, and the option to float certain applications.