All versions of GPS Shield Free V2

* Sending interval is reduced to minimum of 1 second instead of previously 5 seconds. * Bluetooth listening function added. * Now the app can work when the screen is off - reduces battery consumption. * There will be notification service when the app is active - easy to re-access when it is running in background. * The app does not only send the coordinates to Arduino via Bluetooth, but also send the coordinates to Telegram Messenger in the map and message form. * Other minor changes.