Behind the craft
A checkbox is one of the smallest things on a screen, yet it gets tapped more than almost anything else. I wanted ticking off a task to feel like a tiny reward, the way crossing something out on paper does. The border draws itself away as the fill pops in, the tick strokes on, and the label splits along a line so the strike-through feels like it cuts the text. A small shake at the end gives it just enough weight to feel done.