I reported previously (Jan 2016) that the Israeli Dario blood sugar monitor had received FDA approval. Now approval has been extended for the device to be used on the latest Apple iPhones including iPhone 7, 8 and X.

http://mydario.investorroom.com/2018-03-26-DarioHealth-Receives-U-S-FDA-Clearance-for-iPhone-7-8-and-iPhone-X-Smart-Glucose-Meter