Probably thanks to the massive reaction to that little fidget cube thing, more and more toys that “look useless but keep your hands busy” are hitting the market. The most typical recent example is this thing: the fidget spinner. Fidget spinner, as the name suggests, is a top you spin between your fingers. Simple construction, clean look. Hold the center pad, find a way to get it going, and that’s it. It really does spin more easily than your average metal disc—feels super smooth. If you get the force right, you can keep it going for several minutes without stopping. Right now fidget spinners come in two main shapes: two-armed and three-armed. Shape doesn’t change the game, though…