A ball does not bounce off at the angle it hits. A bouncy ball's contact is elastic sideways as well as head-on, so the rebound is set by the spin: throw it under a table and it returns to your hand at exactly 333/343 of the speed it left with.

Every public app is built from a security-scanned skill and must pass a clean scan — skill and frontend — before it can be listed. Have a skill of your own? Turn it into an app — or read the step-by-step walkthrough.