Q:

How get the list of paired bluetooth devices in swift?

I need to get the list of paired bluetooth devices(iOS Devices) as same as the list in  'Bluetooth' section in iOS settings as shown in below picture.

Is it possible?
Have you seen any apps doing this type of functionality?
I have tried the following:
link1, link2, link3, link4, link5, link6
But nothing helped me clearly to get the exact list. I hope there should be a way to achieve this. Please help me by sharing your experience.
Thank you.

A:

It's not possible to retrieve list of paired peripherals from iOS. Neither it's possible to check if specific peripheral is paired.  
Retrieving peripheral which is paired
There are two cases which you need to consider:  

Peripheral may be already connected in the system (iOS connects automatically with some peripherals in order to for example display battery level). In this case peripheral won't be broadcasting and detection using scanForPeripherals won't work.
Peripheral is paired, but disconnected. In this case retrieveConnectedPeripherals(withServices:) won't work.

Therefore to retrieve your peripheral you need to combine both things. First you need to check if it's in peripherals returned from retrieveConnectedPeripherals(withServices:). If not you should scanForPeripherals.  
If you want to retrieve peripheral which is out of range, you can try to use retrievePeripherals(withIdentifiers:), however it may return also not paired devices and it relies on peripheral's UUID which you have to save after pairing.
Detecting if peripheral is paired
There is one way to detect if the specific peripheral is paired. You need to try to read from protected characteristic (which requires encryption - bonding). If you receive expected data, it means that user accepted pairing request. Otherwise you will receive empty response or none.
References
You can read more about Bluetooth in my articles: 

Original answer
Swift – Bluetooth Low Energy communication using Flow Controllers 
How to communicate with Bluetooth Low Energy devices on iOS
Bluetooth Low Energy – background mode on iOS

