The RN41 and RN42 can be used with iOS® but the APL version must be used as this firmware has that feature (RN41APL or RN42APL).
The dual-mode modules such as RN4678/BM78 support Bluetooth® Low Energy (BTLE) and Bluetooth Classic. Most customers use the Bluetooth Classic mode for SPP communication with Android® or Windows® and use BTLE mode for communication with iOS because no MFi chip is needed for BTLE.
However, if you have a need for Bluetooth Classic (iAP) with RN4678/BM78, then you need the MFi chip. There is an I²C interface on RN4678/BM78 to support this.
Since the information on MFi is controlled by Apple®, you need to contact moc.pihcorcim|troppuselppa#moc.pihcorcim|troppuselppa for this information and provide your MFi number. If you use BTLE mode, this is not necessary.