Calla

Privacy policy

Draft for review. Written from the Calla build bible (sheet 24). Have it reviewed before publishing. Last updated 31 October 2026.

This policy explains what Calla ("we", BufferSol Technologies) does with your information. It covers users in the UK (UK GDPR and Data Protection Act 2018), Canada (PIPEDA) and the United States (including the CCPA/CPRA).

The short version

• Your diary (symptoms, sleep, mood, notes, periods, HRT, appointments) is stored on your phone.
• It is copied to our server only if you sign in for backup, so you can restore it on a new phone.
• We never sell your data, never show ads and never use it for advertising.
• You can delete everything at any time, in the app or on this page.

What we collect and why

Health diary (special category data). Stored on your device. If you turn on backup, an encrypted-in-transit copy is stored on our server so it can be restored. Legal basis (UK): your explicit consent, given when you sign in for backup. You can withdraw consent by deleting your account.

Account (only if you sign in). Your Google account identifier and email address, used to identify your backup.

Purchases. If you subscribe to Calla Pro, payment is handled by Stripe (and Google Pay where you choose it). We receive your subscription status and a Stripe customer id, never your full card number.

App activity. Counts of actions (for example "check-in saved", "report exported") without any health values, notes or emails, to understand which features help. Processor: PostHog (EU).

Crash reports. Technical information when the app crashes, with no diary content. Processor: Sentry.

Who processes data for us

MongoDB Atlas (database hosting for backups, EU region), Cloudflare (server hosting), Stripe (payments), Google (sign-in, Google Pay), PostHog (anonymous usage counts), Sentry (crash reports). Each acts on our instructions under a data processing agreement.

How long we keep data

On-device data stays until you delete it or uninstall. Backups are kept while your account exists and are deleted within 30 days of account deletion (usually immediately). Payment records are kept as required by tax law.

Your rights

You can access, correct, export or delete your data, and object to or restrict processing. In the UK you can complain to the ICO (ico.org.uk). California residents have the right to know, delete and correct, and not to be discriminated against; we do not sell or share personal information. Contact support@buffersoltech.com.

Children

Calla is intended for adults (18+).

Changes

We'll update this page and the date above if anything changes, and tell you in the app for material changes.