Activity -> onCreate
this.webView.getSettings().setUserAgentString(
this.webView.getSettings().getUserAgentString()
+ " "
+ getString(R.string.user_agent_suffix)
);
Res -> Values -> strings.xml
<string name="user_agent_suffix">AppName/1.0</string>
Javascript
function() isNativeApp {
return /AppName\/[0-9\.]+$/.test(navigator.userAgent);
}