private static final String TAXIMETER_CHARGE_BROADCAST = 
                                                "com.planetcoops.intent.action.TAXIMETER_CHARGE";

private final BroadcastReceiver mReceiver = new BroadcastReceiver() {

    @Override
    public void onReceive(Context context, Intent intent) {
        // currency, see ITaximeterService.getCurrency()
        String currency = intent.getStringExtra("currency"); //NON-NLS

        /*
         * !! USE THIS TECHNIQUE TO CAPTURE THE FINAL VALUES CHARGED AT THE END OF THE HIRE !!
         *
         * The TAXIMETER_CHARGE Intent is broadcast when a charge is made (on transition
         * from STOPPED to FOR HIRE modes) and will carry the final values for the hire.
         */
        if (TAXIMETER_CHARGE_BROADCAST.equals(intent.getAction())) {
            // TAXIMETER_CHARGE intent
            Log.i(TAG, String.format(
                    "Taximeter Charge:\nExtras: %s%.2f\nFare: %s%.2f\nTax: %s%.2f\n" + 
                    "Total: %s%.2f\nDiscount: %s%.2f\nTip: %s%.2f\n",
                    currency,
                    intent.getDoubleExtra("chargeable_extras", 0d),
                    currency,
                    intent.getDoubleExtra("chargeable_fare", 0d),
                    currency,
                    intent.getDoubleExtra("tax", 0d),
                    currency,
                    intent.getDoubleExtra("total_fare", 0d),
                    currency,
                    intent.getDoubleExtra("discount", 0d),
                    currency,
                    intent.getDoubleExtra("tip", 0d)
            ));
        }

// Receive Taximeter updates
IntentFilter filter = new IntentFilter();
filter.addAction(TAXIMETER_CHARGE_BROADCAST); // Chargeable values
registerReceiver(mReceiver, filter);

How it works
We supply you with a volume license key (VLK) and the current version of the Taximeter APK file which you would then install on each device (see http://www.cnet.com/uk/how-to/how-to-install-apps-outside-of-google-play/) .  The VLK is simply a case-sensitive string of characters which needs to be entered on each device.  The VLK will activate a predetermined number of devices which can be increased as and when required.  The activation is associated with each device and is not transferable.  Warning: Performing a factory reset or installing the app under a new user account (on devices which support multiple users) will cause its device identifier to be regenerated.  Reinstalling the app on a device which has been OTA upgraded to Android O or later may also generate a new device identifier.  As a consequence, a previously activated device will no longer be recognized by our licensing server and a new activation will be required.

Before entering the VLK, make sure you that you have an active internet connection, Wi-Fi or mobile data.  When you first run the app after installing the APK, the app will display the following alert complaining that it is not licensed:

If you have already downloaded and installed Taximeter from the Google Play Store or install the APK using a licensed Google account and want to run it simultaneously on multiple devices, then the procedure is slightly different.  Open the app on each device, and navigate to Menu > Settings > Operator settings > Set volume license key (VLK).  Enter the key here then exit (Menu > More > Exit) and restart the app when prompted.

You can easily check whether a device has been activated.  We append a "+" to the version information in the Menu > About screen to indicate that the app is volume licensed.

As per Google Play Licensing, the app will need to be started once a week with an active Wi-Fi/data connection present to avoid the "Application not licensed" alert appearing see http://www.planetcoops.com/faqs/notlicensed.