We are making MFi hardware and an iOS app. We will want to have the BT device notify our app even if we are not running periodically when certain events happen. I know the CoreBluetooth API is the one to use, but can't tell for sure if that API only works with BT Low Energy devices or if it will also work with regular (MFi of course) BT 2.1 and higher devices. So my question is: Does the CoreBluetooth API only work with Bluetooth Low Energy devices or will it also work with 2.1 devices?