Steht aber auch auf der Racechrono Seite im FAQ, dass es nicht funktioniert:
http://racechrono.com/supportWhich external GPS should I buy?
On iOS:
Dual XGPS 160: In my opinion the best option currently. It’s 10 Hz and supports GLONASS satellites.
VBOX Sport: Great option if you have more to spend. Runs at 20 Hz. Make sure to get the external antenna.
Garmin GLO: Great accuracy and affordable, but it must be connected through iOS Bluetooth settings, and you’ll get only 2.5-3.5 Hz update rate in iOS.
Notice: Popular Bluetooth GPS receivers like Qstarz BT-Q818XT/X and similar will not work on iOS.