Open ski-app-zeta.vercel.app in Safari
Tap the Share button (box with arrow ↑) in the toolbar
Scroll down and tap "Add to Home Screen"
Tap "Add" in the top right
must use Safari — Chrome on iOS won't offer Add to Home Screen
Open ski-app-zeta.vercel.app in Chrome
Tap the three-dot menu in the top right
Tap "Add to Home Screen"
Tap "Add" to confirm
Chrome may show an install banner automatically