[cptskippy]

Although they don't use a browser

That's debatable.

Android WebView is a system component powered by Chrome - https://play.google.com/store/apps/details?id=com.google.and...

[pjmlp]

Only on Android 4.4 onwards.

http://developer.android.com/guide/webapps/migrating.html

Which leaves out 26.2% of Android users:

http://developer.android.com/about/dashboards/index.html