code: public boolean detectAndroidPhone()
     {
        if ((this.initCompleted == true) ||
                 (this.isAndroidPhone == true))
           return this.isAndroidPhone;
  
        if (detectAndroid() && (userAgent.indexOf(mobile) != -1))
           return true;
        // Special check for Android phones with Opera Mobile. They should report here.
        if (detectOperaAndroidPhone())
           return true;
        // Special check for the HTC Flyer 7" tablet. It should report here.
        if (userAgent.indexOf(deviceHtcFlyer) != -1)
           return true;
        return false;
     }
docs: Detects if the current device is a (small-ish) Android OS-based device used for calling and/or multi-media (like a
  Samsung Galaxy Player). Google says these devices will have 'Android' AND 'mobile' in user agent. Ignores tablets
  (Honeycomb and later).
  
  @return detection of an Android phone