[Liwink]

StackOverflow, if it can be regarded as a program.

Spectacle: Easily organize windows without using a mouse on macOS.

https://github.com/eczarny/spectacle

[silentguy]

Only limitation of spectacle is lack of spaces support. You can't create spaces in spectacle. But I use it as my WM and have been very happy with it's simplicity and reliability.