iOS motion

Motion is how a flat screen becomes a product. One purposeful moment beats decoration everywhere. Apply ios-senior-ui-polish.

Four jobs (pick one per animation)

1. Orient — Where did that screen come from? Push/pop, sheets, tab switches.
2. Feedback — The tap registered (highlight, small scale, toggle).
3. Explain — A layout change that would be confusing if it jumped (expand, reorder, number count-up).
4. Delight — Extra, only after 1–3 are solid. Easy to delete. Never required to understand the UI.

If you cannot name the job, delete the animation.

Timing and feel

• 180–300ms for most UI. Springs for elements that settle; easing for fades
• Animate position, size, and opacity together — opacity-only feels cheap
• System: .animation(.snappy, value:), withAnimation, navigation transitions
• iOS 26 controls already animate on interaction — do not wrap them in extra bounce