Android App for Bluetooth Controlled Module

Source code will be our property. App should work on all the Android versions on all android mobiles of all companies like Samsung, oppo, sony and all mobile companies above 4.0 Android version. I am looking for an Android App for controlling Smart Home Automation Products, in which we want to give options of Bluetooth Controlled. Bluetooth Controlled (For Shutter and Gates and Curtains) When user select Bluetooth option then it should directly ask for the permission to connect Bluetooth with a Popup on screen and show open Bluetooth Devices. Its connected device will be Bluetooth and Arduino Nano and relays and after connecting any Bluetooth for the first time, it should ask user to change the password of hardware and without changing the password, it should not move further. There will be a login Pin in the app like Bhim App. Once our Bluetooth and Arduino Hardware is connected to one registered mobile number after that it can not be connected to any other mobile.