Window Tidy vs AROW
When comparing Window Tidy vs AROW, the Slant community recommends AROW for most people. In the question“What is the best window manager for Mac?” AROW is ranked 22nd while Window Tidy is ranked 33rd. The most important reason people chose AROW is:
If you use external monitors, the app is useful. It also supports retina screen without problems.
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Pros

Pro Easy drag and drop interface
When you want to resize a window you just drag it on the screen and your configured workspaces appear immediately, semi-transparent. Then you just drag and drop your window above the configuration that you want to use.

Pro Allows multiple workspace configurations
Window Tidy facilitates not just window sizes, but windows that are precisely sized to fit together to fill up the screen.

Pro Fine tune window sizes
You can set up windows to fit as large or as small of an area on your screen as you would like. For example, if you want a 1/3 left, 1/3, center, 1/9 top right, 1/9 center right, and 1/9 bottom right, you can and it is easy to set up.
Pro Support for multiple monitors
If you use external monitors, the app is useful. It also supports retina screen without problems.
Pro Customizable options
You can customize the app in Option, for example, where you can change the appearance of the preview outline, adjust the width of the recognition areas, and set keyboard hotkeys for quick window snapping.
Pro Define OS X window buttons
AROW enables you to change the actions of OS X’s window buttons. It only requires either a right or a left-click for the action to take place.
Pro Smart Panel to move and resize windows
The customizable grid panel is very intuitive and is an accurate way to resize and move windows. Simply drag your mouse across its grid, the window will be moved, and resize to the exact position instantly.
Pro Easy ways to snap windows
Simply drag windows to the edges of your Mac’s screen. Once the cursor reaches the screen’s edge, the window will automatically move and resize to fill exactly half or quarter of the screen.
Cons
Con Doesn't work - has been abandoned

Con Workspaces don't show up when you drag a window
Workspaces will only appear on one desktop, but not the others.
Con Trouble with GUI
Yosemite (10.10.5) it works but it's impossible to open the application GUI.
