privacy policy · effective 2026-05-03

we collect basically nothing.

a short privacy policy for an app that is trying very hard not to have your data in the first place.

what stays on your device

atrophy stores one thing in your iphone's local app storage:

diagnostic history

a local log of past diagnostic runs (score, tier, and timestamps), kept under the atrophy.diagnosticHistory.v1 key in iOS UserDefaults. this is what powers the in-app history view. it never leaves your device. you can clear it by deleting and reinstalling the app.

that's the list. your individual answers, written responses, and the prediction-vs-measurement gap for the current run live only in memory and reset every cold launch by design. only the summary record is persisted.

if you tap the "lifetime tier" option in the paywall, the app opens your system mail composer with a prefilled message addressed to atrophy.app+lifetime@gmail.com. atrophy does not store the email address you send from, and does not send anything itself — your mail provider does. if you do not send the message, nothing leaves your device.

what leaves your device

the only outbound network calls atrophy makes are to apple's storekit:

• fetching the price and availability of the monthly and annual subscriptions.
• starting a purchase when you tap "practice calibration" or another paywall action.
• checking your active subscription on app launch, or when you tap "restore purchases."

these calls are governed by apple's privacy policy. atrophy never sees your apple id, payment method, or personal billing information. apple handles all of that and only tells the app whether you have an active subscription.

two other things leave the device only at your explicit request:

• photo library (add-only). if you tap "save to photos" on a share card, the app writes one image to your photo library using the system add-only permission. it never reads existing photos. iOS will prompt you the first time.
• mail composer. the lifetime-tier action described above hands a prefilled message to your mail app. nothing is sent unless you tap send.

what we don't do

• no analytics. no posthog, mixpanel, amplitude, google analytics, or anything like that.
• no crash reporting beyond apple's optional, opt-in testflight diagnostics.
• no third-party sdks and no third-party dependencies. the app is pure swift on top of apple's frameworks. bundled content is plain JSON loaded from the app bundle.
• no advertising identifiers. no app tracking transparency prompt, because there is nothing to track.
• no social sign-in. no accounts. no login.
• no fingerprinting, no device identifiers, no ip-based geolocation.

changes to this policy

if we ever start collecting data, like syncing assessment history to icloud or sending anonymous aggregate stats to a server, this page will be updated and the change will be called out in the app's release notes before it ships. we will not quietly turn on data collection for existing users.

children's privacy

atrophy is not directed at children under 13. we do not knowingly collect personal information from children. if you believe a child has provided data through the app, contact us and we will delete it. this section is intended to address children's privacy requirements including coppa and gdpr article 8.

california privacy

we do not sell or share personal information as defined by the california consumer privacy act. since atrophy does not collect personal data, there is nothing to sell, share, or opt out of.

your data rights

under the gdpr, you may have the right to access, rectify, erase, restrict processing of, and port your data. since atrophy stores diagnostic history only in on-device UserDefaults and never transmits it to us, exercising your right to erasure is as simple as deleting the app. for any data rights request, contact atrophy.app@gmail.com.

contact

questions about this policy: support page.