活动- > onCreate

this.webView.getSettings().setUserAgentString(
    this.webView.getSettings().getUserAgentString() 
    + " "
    + getString(R.string.user_agent_suffix)
);

RES- >值-> strings.xml

<string name="user_agent_suffix">AppName/1.0</string>

Java脚本

function() isNativeApp {
    return /AppName\/[0-9\.]+$/.test(navigator.userAgent);
}