Apple - Snap feature for Mac?
For window arranging:
- SizeUp $13
- Divvy $14
- Breeze $8
- ShiftIt Free
- Mercury Mover $20
- Optimal Layout $14
- Cinch $7
- Moom $10
Spectacle was mentioned in a question that was marked as duplicate of this one, but has not yet appeared here. It is also open source:
- Spectacle at Github
Also, OS X El Capitan (OS X 10.11) will have a side-to-side snap feature when it is released later in 2015 using Mission Control.
You may also be looking for SizeUp (13$). That emulates the Windows Snap features better, I think.