Q: Why can't I see my BLE devices on iOS Bluetooth Settings page
A: According to Apple support it is not possible to see BLE devices listed on the Bluetooth Settings page. Only Bluetooth 2.1/3.0 devices are listed such as keyboards and headsets (source). For BLE devices you must use the device's own app or any other 3rd party app which uses CoreBluetooth.
However, it seems that iOS does list BLE devices when they advertise some of the adopted services such as the Heart Rate service. By advertising this service you can get your device visible in the Bluetooth Settings page. To test this by following these simple steps:
- Create an soc-empty project
- Add the Heart Rate service in the Visual GATT Editor
- Tick "Advertise" and click "Generate"
- Build and flash the project
(Disclaimer: We could not find any information source to verify that iOS does indeed list BLE devices when certain adopted services are advertised)