There are many Mac window managers out there and Moom is by far the best. Some like Divvy are mouse based, while others rely on the keyboard. Moom splits the difference and offers both forms of input control along with crazy customization options for power users. Arguably best of all, Moom has a fairly low memory footprint.
One little feature I use every day is their arrange windows option. Just press a key combo and every app gets resized and moved back to a custom arrangement of your choice. I’m the type of user that constantly shifts windows around to get stuff done to the point where after a a few hours I’ve got a pretty chaotic desktop. With an arrange windows keystroke I’m back to a clean screen.
This feature becomes amazing when you’re switching between using an external Cinema Display and running a Macbook Air solo. If you’re ever experienced it you know the annoyance of all your windows bunching up in a mess when you switch display modes. No more with Moom: I’ve got two different arrange window options (Macbook Air solo, Macbook Air + Cinema Display) and trigger each after I plug/unplug from the Cinema Display.
Highly recommended for $5. Do buy the direct sales version off manytricks.com though; Moom is a non-sandboxed app which makes it DOA for the Mac App Store going forward.