Alke can run in your browser, but you can pin it to your home screen and it'll open like a native app. Full screen, no browser bar.
Open Chrome → tap the three-dot menu (top right) → "Add to Home Screen" → confirm.
Open Safari → tap the share button (the box with the arrow, bottom center) → "Add to Home Screen" → confirm.
Once installed, tap the icon like any other app.
Rotate your phone horizontally and you are in.