Simple APP that reads any value or text printed to the arduino serial using a HC-07/06/05 bluetooth module or any other. There is no need to change anything in the arduino code, simply using SerialPrintln(); will make the app read it while connected to bluetooth. You can add any sensor to display its value in this app, its a multifunctional. Click on the Schematic & code button in the app to find more info, or follow the link for the instructable
You can contact me for the source code.