Polly Privacy Policy

Last updated: 23 April 2026

Polly (“the app”) is a pollen-allergy companion built by Adam Mierzwa (“we”, “us”). This policy explains what data the app handles and why. We collect the minimum needed to make the app useful, we do not sell data, and we do not run ads.

Data stored on your device

Your diary entries, including the date, how you felt, any notes you write, and the symptoms you log.
Your profile: display name, selected allergens, notification preference, and home coordinates.
Cached pollen forecasts tied to the coordinates you looked up.
This data is stored locally on your device using Apple’s SwiftData framework. Your free-text notes and display name never leave your device or your iCloud account.

iCloud sync

If iCloud is enabled on your device, your diary and profile sync across your own Apple devices through Apple’s CloudKit service into your personal private iCloud database. We do not have access to this data. You can disable sync in iOS Settings at any time.

Location

Polly requests “When In Use” location permission to fetch the local pollen forecast and air-quality data. Coordinates are requested at roughly 1 km accuracy — not precise GPS — and are sent only to the forecast providers listed below. We do not store a history of your locations on any server.

If you decline location, or prefer a fixed home city, you can set one manually in Profile → Home city. The selected city’s coordinates are stored on your device and sent to the forecast providers in the same way as a device-provided location.

Subscriptions

Subscription purchases are handled by Apple’s App Store. We use RevenueCat to verify entitlements (e.g. whether “Polly Pro” is active). RevenueCat receives a random anonymous identifier and your purchase receipt — it does not receive your Apple ID, email, or name. See RevenueCat’s privacy policy.

Analytics

Polly uses PostHog, a privacy-focused product analytics service, hosted in the EU, to help us understand how the app is used and where to improve it. We send:

A random anonymous identifier generated on your device. It is not linked to your Apple ID, email, name, or any other account you hold elsewhere.
Event names describing actions like opening a screen, completing onboarding, saving a diary entry, or viewing the paywall.
Aggregated profile properties: the count of allergens in your profile (not the allergens themselves), whether notifications are enabled, whether you have set a name (as a true/false flag, not the name itself), whether you have granted location (as a true/false flag, not the coordinates), subscription status, and days since install.

We do not send your display name, your free-text diary notes, your precise coordinates, your Apple ID, or any direct identifier. PostHog does not perform cross-app or cross-site tracking. Polly contains no advertising SDKs. See PostHog’s privacy policy.

Feedback form

If you open the in-app feedback sheet, it loads a web form hosted at mierzwa.net. Your anonymous PostHog identifier is passed as a query parameter so that feature votes and submissions can be attributed to the same anonymous person across the app and the web form. Only content you actively submit (feature suggestions, votes, or private messages you write) is saved.

Third-party services

Google Pollen API — receives your coordinates to return a pollen forecast. See Google’s privacy policy.
Open-Meteo Air Quality API — receives your coordinates to return hourly and historical pollen and air-quality data. See Open-Meteo’s terms.
Apple — StoreKit handles purchases; CloudKit handles sync. Governed by Apple’s privacy policy.
RevenueCat — verifies subscription entitlements as described above.
PostHog (EU) — product analytics as described above.

Children

Polly is not directed at children under 13 and does not knowingly collect data from them.

Your rights

All diary and profile data lives on your device or in your iCloud account. To delete it, remove the app from your device and delete its iCloud data in iOS Settings → Apple ID → iCloud → Manage Storage. We have nothing to delete on our side because we do not store diary data on our servers. If you would like your anonymous PostHog analytics identifier deleted or any feedback you submitted removed, email us at the address below and we will action it.

Changes to this policy

If we make material changes, we will update the “Last updated” date above and, where appropriate, surface a notice inside the app.

Contact

Questions: privacy@mierzwa.net