Sync'd - A Social Calendar App (Sync'd for short) uses the Microsoft Graph Toolkit to connect to your personal Microsoft Outlook Email address. After signing in the user has the option to allow certain read/write access to their calendars allowing Sync'd to read and write to their calendars and even send invites via email. For more information on how the Graph Toolkit works and how Microsoft protects your data read here: https://docs.microsoft.com/en-us/legal/microsoft-apis/terms-of-use?context=graph/context#8--confidentiality.
I use firebase to store certain information to be displayed across the app. The only identifying information that is stored in the database is the users first and last name (as it appears in their connected microsoft account) and also the event list that the friend group creates. No one outside of the Sync'd team has access to read that information. To learn more about how Firebase handles their Security read here: https://firebase.google.com/support/privacy/.
If you have any concerns, do not hesitate to contact me at jaylyn.1b@gmail.com.