frontit inspector
Browser primitives for the states and values the platform keeps to itself. Open this on a real device — that is where these answers differ.
createScrollState
Touching, scrolling, touch-scrolling and momentum as four separate states. Scroll, flick, hold a finger still mid-scroll, and grab a coasting scroll to see them disagree.
toPx
Every CSS unit this browser resolves, in pixels, right now.