Privacy Policy

Your Account

• Start without an account: you can use Sizebook without signing up. The app creates an anonymous account tied to this device through a random token stored in your iPhone's keychain. We do not ask for your name, email address or phone number.
• Sign in with Apple: if you choose it, we store only a one-way hash of the user identifier Apple gives us, so you can recover your data on another iPhone. We do not receive or store your email address or your name from Apple.
• Sessions: we store a SHA-256 hash of your session token, never the token itself.

Information We Collect

Data You Provide

The following is stored on our servers (Cloudflare Workers and a Cloudflare D1 database) so that it can be shared with the groups you choose and restored on your devices:

• Your profile: the name, emoji and color you choose.
• Your sizes: your size per category and per brand, with fit, notes, size system, the date each size was last checked and a history of up to 12 earlier sizes.
• Body measurements: height, weight, chest, waist, hips, inseam, foot and head, if you enter them.
• Gift notes: likes, dislikes, colors and favorite brands.
• Your wishlist: title, optional link, price and note for each item.
• Groups: groups you create or join (name, type, emoji, invite code, sharing settings and edit policy), Secret Santa draws (who gives to whom) and wishlist claims (“I'll get it”).

Data Collected Automatically

• Anonymous usage analytics: we use TelemetryDeck to understand which features are used (for example “a size was saved”, which category, and counts). Analytics never include names, sizes, brands, notes or group names, and the user identifier is hashed on your device before it is sent. See TelemetryDeck's privacy policy.
• In-app purchases and subscriptions: Premium is handled by Apple and RevenueCat. RevenueCat receives a random app user ID (no name or email) and Apple's purchase data to validate the purchase. We never see your payment details. See RevenueCat's privacy policy.
• IP addresses: we do not store IP addresses. To limit abuse, at sign-up we keep a keyed hash (HMAC) of your IP address combined with the date, which cannot be turned back into the address. Cloudflare's rate limiting uses the IP address transiently.
• Crash and diagnostic data: only what Apple provides through App Store Connect, and only if you chose to share it with developers.

Data Kept Only on Your iPhone

• A cache of your data, so the app works offline.
• Unit and onboarding preferences.
• Size check reminders, which are local notifications scheduled on your iPhone. They are not sent through our servers.
• Groups that live only on your iPhone, which stay on the device unless you choose to share them.

Who Can See Your Sizes

• Per group choices: each group sees only what you choose to share with it, section by section: clothing, underwear and swim, footwear, accessories, measurements, and gift notes and wishlist. Our server applies these choices before anything is sent to other members.
• Only me: entries marked “Only me” are never sent to any group.
• Secret Santa: in Secret Santa groups set to “only my giver”, only the person who drew you sees your sizes. Each member only ever sees their own pair of the draw.
• Wishlist claims: the owner of a wishlist never sees who claimed their items.
• Shared editing: if a group allows members to edit each other's sizes, they can only edit what you share with that group, never your “Only me” entries.

People Without the App

A member of a shared group can add people who do not use the app, for example children or grandparents. Their name, emoji, sizes, measurements and wishlist are visible to that group. The person who adds them, typically a parent or guardian, is responsible for that information and for having the right to share it. Groups that live only on your iPhone stay on the device unless you choose to share them.

How We Use Information

• To store your sizes and share them with the groups you choose.
• To restore your data when you sign in with Apple on another iPhone.
• To understand which features matter and fix what breaks, using anonymous analytics.
• To validate Premium purchases.
• To limit abuse of our servers.

We do not track you, we do not show ads, we do not work with data brokers, and we do not sell your data.

Third-Party Services

• Apple: Sign in with Apple, App Store purchases, and crash reports only if you opted to share them with developers.
• Cloudflare: hosts our servers and database.
• TelemetryDeck: anonymous usage analytics.
• RevenueCat: in-app purchase and subscription validation.

Data Retention and Deletion

• Your data is kept while your account exists.
• Profile > Delete my account removes your account, your sizes and profile, your sessions, your group memberships and your wishlist claims, and clears your Secret Santa draws.
• Groups you created pass to another member, or are deleted if nobody else is in them.
• People without the app that you added to groups owned by others stay in those groups, and that group can remove them.
• Contact us to request deletion of anything else.
• RevenueCat purchase records follow RevenueCat's own retention policy.

Children

Sizebook is not directed at children under 13 and we do not knowingly collect personal information from them. Adults may record sizes for their children as described in “People Without the App” above. If you want a child's information removed, contact us and we will delete it.

Your Rights

You can see and correct everything we hold about you directly in the app, change what each group sees at any time, and delete your account from Profile > Delete my account. If you want a copy of your data, or believe we hold something about you that you cannot reach in the app, contact us and we will help.

Changes to This Policy

We may update this page as the app evolves. Material changes will be noted in the app's release notes.

Contact Us

Questions about this policy or your data? Please contact us by email.