Better Window Manager!

Using Spectacle you can view multiple documents side-by-side, move windows to other displays, or even focus your full attention to a single task.

Aquasnap is a powerful window manager that helps you arrange and organize multiple applications on your desktop with minimum effort. It allows you to achieve maximum multitasking, especially if you own a high-resolution monitor or a multi-monitor setup.

BetterTouchTool is a great, feature packed app that allows you to configure many gestures for your Magic Mouse (1 & 2), Macbook Trackpad and Magic Trackpad (1 & 2) and also Mouse Gestures for normal mice. It also allows you to configure actions for keyboard shortcuts, normal mice buttons and the Apple Remote. In addition to this it has an iOS companion App (BTT Remote) which can also be configured to control your Mac the way you want.

WinSplit Revolution is a small utility which allows you to easily organize your open windows by tiling, resizing and positioning them to make the best use of your desktop real estate.

BetterSnapTool is a utility that mimics Windows 7 Aero snap, allowing you to easily manage your window positions and sizes by either dragging them to one of your screens corners or to the top, left or right side of your screen. This lets you easily maximize your windows or position them side by side.

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. This is especially useful in netbooks, with respect to the small screen and touchpad. It simply allows you to do more with less mouse movements.

GridMove - A window management tool that can quickly arrange your windows into desktop grids.GridMove is a program that aims at making windows management easier. It helps you with this task by defining a visual grid on your desktop, to which you can easily snap windows. This program comes bundled with some predefined grid templates, that can be easily swaped, but also has ways of creating custom grids or sharing grids made by others.

HyperDock adds Windows 7 like features and more to Mac OS X.

Windownaut is versatile window management app that let's you define keyboard shortcuts and active areas on your screen to resize an position the windows on your desktop.

MaxSnap is a powerful window manager which lets you:

SizeUp allows you to quickly position a window to fill exactly half the screen (splitscreen), a quarter of the screen (quadrant), full screen, or centered via the menu bar or configurable system-wide shortcuts (hotkeys). Similar to "tiled windows" functionality available on other operating systems.