Mac window snapping to edges and custom zones

Drag a Mac window to a screen edge, or to a snap area you drew, and drop it there.

Snap is a drag. The window goes to a screen edge, or to an area you drew because halves are not the size you want. A flick of the cursor without dragging is Quick Throw.

Snap to an edge

Grant Accessibility for Gablet, then quit and reopen it.
Drag the window to the screen edge until it snaps.

Or snap to an area you drew

In Settings, draw the snap area. Set the size and the position.
Drag the window onto that area.

You can download Gablet. macOS 11.5 or later. 7-day trial, then a paid license. If nothing snaps, Accessibility is off.