Privacy policy

Last updated 21 October 2026

Tandem is a small app for people who live together to share a shopping list, chores, hosting plans and spending. This page explains what it stores, where, and how to remove it.

What Tandem stores

• Your account: the email address and display name from your sign-in (Google, Sign in with Apple, or email and password), collected the first time you sign in. Firebase Authentication handles all three. With Sign in with Apple, Apple shares your name only at that first sign-in, and if you choose Hide My Email, we receive an Apple relay address instead of your own. Passwords are handled by Firebase Authentication and are never visible to us.
• Your home: the shopping list, chores, hosting events, guests, prep tasks, spending records and budgets you and the other members of your home create. Everyone in the home can see this data; that is the point of the app.
• Presence: whether you are currently in shopping mode, so the others can see you are at the shop. This expires on its own after a few hours.
• A push notification token for your device, so the others in your home can notify you (for example when someone adds to the list). You can turn these notifications off in Settings.
• Barcodes you name: if you scan a product the database does not know and give it a name, that name is remembered for your home.

Email updates

If you sign up for updates on tandem.casa, we store your email address and the time you signed up, once for each sign-up. Duplicates are removed before any email goes out. It is stored in Firestore, in the same Firebase project as the app, in London (europe-west2). We use it only to email you updates about the app. It is never shared or used for anything else. You give consent by signing up, and you can withdraw it at any time. We keep the address until you ask us to delete it or we stop sending updates. To be removed, email hello@tandem.casa and the address is deleted.

What Tandem does not do

• No advertising, no analytics trackers, no selling or sharing of your data with anyone.
• Receipt photos are read on your device to find the total. The photo is not uploaded and is not kept.
• Barcode scanning uses your camera only while the scanner is open. Nothing is recorded.
• Your location is never collected.

Third parties

• Google Firebase (Authentication, Firestore, Hosting) stores the data above. The database is located in London (europe-west2). Google's privacy terms apply to that infrastructure.
• Expo delivers push notifications and app updates. Notification content is generated by the app on your household members' devices; Expo relays it.
• Open Food Facts, a non-profit open database, answers product searches and barcode lookups. Your search terms and scanned barcodes are sent to it; your identity is not.

Who can see what

Only members of your home can read your home's data, enforced by database security rules. Someone who enters your invite code sends a request; nothing is visible to them until an admin approves it. The person who creates a home is its owner and can name admins. Admins approve join requests and can remove members. Anyone can leave.

Deleting your data

Settings, then Delete account. This removes you from every home you are in, deletes your profile, and deletes your sign-in. Data that belongs to a home you shared (for example items you added to a list) stays with the remaining members, without your account attached. If you are the last person in a home, you can delete the home first from Home settings.

Children

Tandem is not directed at children under 13 and does not knowingly collect their data.

Changes and contact

If this policy changes, the date above will change with it. Questions or requests: hello@tandem.casa.