Spectacle is an open-source windows manager for MAC which helps users easily organize windows with or without using a mouse. 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.
Spectacle makes use of several keyboard shortcuts that trigger specific window actions. A window action is nothing more than a command that tells Spectacle how to change the size and/or position of a particular window.
A keyboard shortcut consists of one or more modifier keys paired with a character key. The default keyboard shortcuts can be changed at any time. Use new key combinations to trigger window actions, or clear particular keyboard shortcuts to disable window actions entirely.
You can also click to expand the Spectacle menu from top menu bar to quickly resize and reposition current window or app on Mac.
Unfortunately, after almost a decade of on-and-off development, this project is not being actively maintained. You can still download and use it for free at your own risk. Or you can use alternatives below.
Magnet for Mac: a windows manager for Mac to keep your workspace organized. Magnet declutters your screen by snapping windows into organized tiles.