We have used an existing app to connect to the BLE service that we implemented on Raspberry Pi. This app, called BLE Scanner, is very general purpose and would work for any kind of BLE device. However, we need a more specialized app that only reads measurements and abstracts away details of the BLE protocol, such as device scan, services, and service characteristics. In this section, we will implement an Android app to connect to the Raspberry Pi BLE. We need to install the Android Studio for this purpose. Android studio is specifically designed for Android app development by Google. You can read more about it by visiting http://developer.android.com/tools/studio/. You can find instructions for installation at http://developer.android.com/sdk/. We will use a real device to test our app and not the built-in emulator. For this purpose, you may need to install device drivers specific to your Android phone and make configuration changes to the Android Studio installation...