Screenshots
Gluestick 1.0.2 on macOS Tahoe.
Fill the gap
Snap a window and your other windows appear in the space left over. Click one, press its number or type to filter. The windows here are samples. Yours shows your own.
Every layout, one shortcut away
Halves, quarters, thirds, maximize, center and restore, from the menu bar or the keyboard. Add ⌘ to move a window to your other display.
Settings
Turn the picker, previews and edge dragging on or off, leave space between windows, and change any shortcut.
Install
Open the download and drag Gluestick into the drawer, which is your Applications folder.