(BLE) Bluetooth is fairly simple to integrate, typically it's a SoC with code - you push code to it that beacons out a gatt structure which has your device ID, and list of r/w attributes
You can find demo apps for android and ios that will scan for the beacons, and then allow you to modify those attributes
I tried this with an eval board from silicon labs- thunderboard sense 2 (It's about 30$US), and about half a day I was able to light the leds or read the sensors on it from a phone
most of that time was working out the license for the s/w downloaded and getting the updates installed - It has an eclipse based IDE with a lot of available SDK's
It's based on single chip arm+radio MCU called gecko (they are about 4-7$)
Haven't tried on xcode yet, but here is an example
Learn how to develop Bluetooth LE apps for iOS! See how connections are made, data is transmitted and more behind the scenes using the Swift programming language.
On android though it was fairly simple to write code that accesses
you can start here if you have adk installed ->
https://www.bignerdranch.com/blog/bl...energy-part-1/