I may be missing something simple or straightforward here, but if the Adafruit BLE feather has a bluetooth chip why isn't the iPhone not seeing it (in Settings->Bluetooth->Devices) but when I install the Bluefruit Connect app, its able to see it.
Unless the system (BT HW on the phone) sees it the app cannot see it. So what is preventing the settings from showing it?
The device settings in iOS shows legacy bluetooth devices, such as handsfree audio devices, keyboards and mice. It doesn't show BLE devices unless there is an active connection to the device (or the device has been bonded, which isn't common with Bluetooth Low Energy devices).
The Bluefruit app will search for devices that are advertising the GATT service in which it is interested. Bluetooth settings does not do this.