Website requirements

Almost any public website works. These points make the difference between “works” and “feels native”.

Must have

• HTTPS with a valid certificate and no mixed content (HTTP images or scripts on an HTTPS page are blocked).
• Publicly reachable: no password protection, coming-soon page or IP allow-list.
• A responsive layout with a viewport meta tag.

Strongly recommended

• A mobile menu that works with a thumb; the app has no browser back button in the toolbar (Android’s back gesture works).
• Fast pages: aim for under 3 seconds on 4G. Compress images and avoid heavy third-party scripts.
• Links to other sites should be intentional; by default they open in a Chrome Custom Tab so users do not get lost.

Things that break the experience

• Security plugins that block the WebView user agent. Allow user agents containing wv or ApkZio.
• X-Frame-Options is irrelevant (the app does not use an iframe), but Content Security Policy rules that block navigate-to can interfere.
• Pop-ups that open new windows: the app opens them in-place or in a Custom Tab.