You can unsubscribe from emails from the More tab in your Cronometer account.
In the mobile app go to:
More > Account > Privacy > Toggle off I agree to receive newsletters and promotional emails
On the web go to:
More > Account > Privacy > Toggle off Send me newsletters and promotional emails
Please note, you can also unsubscribe from Cronometer's mailing list by selecting the link next to Unsubscribe From This List at the bottom of the emails we are sending.