I have also answered Dani76, I hit you:
I explain a little about the clock.
Specifically, the clock that works without continuously carrying the mobile or receiver Dexcom G5, is the Sony Smartwach 3. The XDrip+ application is discharged in the mobile and from the mobile the clock is configured so that it works as a "collector" that the Americans say, let's make a receiver.
When you have the mobile nearby the clock data will be passed to the mobile and from there if you want to be able to upload them to Nightscout if you want to see your values when you are in school for example.
Here you can download the xDrip+ application
Link
There are variis groups where you can get a lot of information about Dexcom/XDrip and Nightscout.
Look for it as Nightscout Spain
