For sharing your data on iOS, please follow this article about the Share tab in the Withings App.

For Android, you can also use the Share tab here or the Measure tab, with the steps below:

1. Open the Withings App.
2. Select a blood pressure measurement in the Measure tab.
3. Tap See my trend.
4. Tap the three dots at the top right of the screen.
5. Tap Share with my doctor.
6. Enter the email of your doctor.
   You can choose to send all your blood pressure measurements or the measurements over the past 3 months/weeks. You can also set a periodical reminder.
7. Tap Confirm.