Magnet (Mac OS X App)

・Left/Right/Top/Bottom Halves of the screen supported
・Left/Center/Right Thirds of the screen supported
・Left Two Thirds & Right Two Thirds of the screen supported
・Fullscreen & all four Quarters of the screen supported
・Activated by dragging (optional)
・Activated by keyboard shortcuts (customizable)
・Operated via Menu Bar icon
・Runs both on Retina and regular displays
・Up to six external displays supported
・Built to run on all macOS versions since 10.9 Mavericks
・macOS 10.12 Sierra optimized