In reading the advertised info from Dario, it says that the Dario glucometer works with smartphone "Apple iOS devices, on iOS 6.1 or above." I took that to mean it would work on the iPhone 7, which is "above" the iPhone 6.
I used the adapter that comes with the iPhone 7, and made all of the suggested adjustments that Dario instructions say to do when the message on the downloaded app is that the Dario glucometer is "not connected" to the iPhone. No luck. Still got the "unconnected" message. So, I called Darios Customer Service. The person I spoke with was very nice, telling me that the present Dario glucometer is not compatible with the IPhone 7!!!
60lcand fit about Dario Health, v3.3.0