Complete Back-end for iOS and Arduino Project with HM10 BLE

I have a project which is near completion however I am having difficulties with the back end. It involves and iOS app, which has been made in Xcode, and an Arduino, which has been programmed, apart from the bluetooth part. They are connected via the BLE HM10 module, however I can't add the code for bluetooth in iOS app and arduino. All that I require is to finish off the back-end of this project. How much would you charge for this service?