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Better Snap Tool (App Store) - This one actually looks very good. similar to Cinch but also includes keyboard shortcuts. With a ~$2 price tag it beats the the competition in terms of price. I have yet to try it.
Hyperdock (App Store) - Looks to include the Has mouse snap feature, plus it allows previews of applications like Windows 7. Unfortunately for me, it is not viable on the iMac as it is missing keyboard shortcuts for predefined window sizes.
Better Magnet (App Store) - Also looks good too.
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