You will need a Garmin Flight Stream 110, Flight Stream 210, or a Flight Stream 510 to connect ForeFlight Mobile to your GNS or GTN* Garmin avionics. The Flight Stream 510 is only compatible with GTN 650 and 750 series Navigators.
Contact your avionics shop for more details on pricing and installation or see Garmin's website for more information about the Flight Stream 110/210.
*GTN 650/750 only. GTN 650Xi and GTN 750Xi are not supported.