Contraptions are any sort of combination of cells that serves a specific purpose, preferably in the smallest amount of cells necessary. There are many, in fact theoretically an infinite amount, of contraptions. The ones listed of course cannot be complete.
Keys are one of the simplest contraptions. They allow for a rotator to be moved easily for a theoretically infinite amount of time while leaving no trail behind. If a slide cell is added, it moves at 2 ticks per frame.
Nukes are machines which fill the entire grid at an exponential pace. These generators duplicate each other, exponentially increasing in quantity.
