Amethyst arranges application windows on screen (or on a specific space) into a tiled arrangement based on one of several models. (I am using the “tall” setting.) It takes a bit of getting used to, but I like it now that I have sort of got the hang. The key thing to grok is that it arranges all visible windows, so if you have a ton of visible windows, hide everything you don’t need at the moment. Un-hiding a window will cram it into the existing arrangement — by shortening one window to make room for another, for example. So you can pop up a terminal window and have it fit into your view while you use it, and when you hide it, the window(s) that made room for it will expand back to their previous size. It’s controllable by keyboard, so you can float, resize, and cycle through windows without touching the trackpad. Quite cool.