Privacy Policy — Compresser

Last updated: 2026-05-06 · Effective date: 2026-05-06

1. Who we are

Compresser is a mobile app for on-device compression of images, videos, audio files, and PDFs. Privacy is fundamental: compression runs locally on your device and your files are never uploaded to our servers — they never leave the device for any third party to read, copy, or analyze.

Data controller: Maciej Siemiński — the developer of Compresser. Contact: mail@macsiem.dev

For the version of the app distributed via Google Play, the data controller is LICENCEPRO POLSKA Sp. z o.o., ul. Huculska 6, 00-730 Warszawa, Polska.

This Privacy Policy explains what personal data Compresser processes, how, why, and what rights you have.

2. Plain-language summary

Compresser runs entirely on your device — your files are never uploaded to our servers. We integrate Google AdMob for banner and interstitial ads, Sentry for crash reporting, and Apple / Google billing for in-app purchases. We do not collect your name, email, address, or precise location. You have full GDPR rights including access, deletion, and portability — most exercisable directly in the app or by writing to mail@macsiem.dev.

3. Data we process

3.1 Local-only data

The app stores locally on your device:

• user preferences (compression quality, default formats, theme),
• onboarding completion flag,
• compression history (timestamps and per-file statistics — without file content).

These data are stored entirely on your device and are never transmitted to our servers or any third party.

3.3 Diagnostic data (Sentry)

Compresser integrates Sentry (sentry.io) for crash and error reporting. Sentry collects:

• error stack traces (crash logs),
• device info (model, OS version, locale),
• app version and build number.

Sentry does not collect your content (entries, files, vaccination records, photos, archives), usernames, or other PII. Diagnostic data is retained by Sentry for up to 90 days.

3.4 Advertising (AdMob)

Compresser shows non-invasive ads on Home, Result and Settings (banner) plus interstitial after compression batches. Ads are delivered by Google AdMob, whose SDK collects:

• the Advertising ID (Android Advertising ID / Apple IDFA), shared with Google to serve ads;
• diagnostic data (device model, country-level location, language).

Ads may also be delivered through AdMob mediation partners: Meta Platforms, Inc. (Meta Audience Network, privacy policy) and Unity Technologies (Unity Ads, privacy policy). These partners receive ad requests under the same configuration — non-personalized ads.

Default mode is non-personalized ads. On iOS, the App Tracking Transparency (ATT) prompt asks for your consent before any tracking-grade identifier is used; on Android you control the Advertising ID under system Settings. Ads can be permanently disabled via the Lifetime / Premium IAP.

3.5 In-app purchases (IAP)

Compresser offers paid features through Apple In-App Purchase (iOS) and Google Play Billing (Android). When you make a purchase:

• Apple / Google process all card and account data — we never see your card number, billing address, or full account information;
• Apple / Google return a purchase token / transaction receipt that Compresser stores locally to validate entitlement;
• restore purchases re-fetches your existing entitlements from Apple / Google.

Available products: lifetime unlock, optional tip jar, premium annual subscription.

3.6 Device permissions

• Photos / Media (READ_MEDIA_IMAGES / PHPhotoLibrary): add or process images from the gallery (optional unless required for app's core function).
• Files (READ_EXTERNAL_STORAGE / iOS Files): pick documents/archives (only when you choose a file).
• Notifications (POST_NOTIFICATIONS / UNUserNotificationCenter): reminders and operation status (optional).
• Vibrate (VIBRATE): haptic UI feedback (optional).

Each permission is requested contextually. You can deny any permission and still use the core features (where applicable).

3.7 What we do NOT collect

• Your name, email, phone number, address (no account is required).
• Contacts list, calendar, SMS, call logs.
• Precise location.
• Browsing history outside the app.
• Biometric data (Face ID / Touch ID is used only as a system-level lock and never leaves your device).
• Health, financial, or payment card data.

4. Why we process this data (purposes)

• Run the app on your device — local storage and (where present) encryption let your data persist between sessions.
• Improve stability — Sentry diagnostics help fix crashes that affect your usage.
• Sustain the free tier — AdMob delivers non-invasive ads to fund users who do not buy premium.
• Process purchases — Apple / Google billing fulfils premium entitlements you choose to buy.

5. Legal basis (GDPR Article 6)

For users in the European Economic Area, United Kingdom, and Switzerland:

• Performance of a contract (Art. 6(1)(b)) — running the app, processing your purchases.
• Legitimate interest (Art. 6(1)(f)) — Sentry diagnostics, fraud / abuse prevention, non-personalized advertising. Our interest is improving stability and sustaining the free tier; this does not override your fundamental rights.
• Consent (Art. 6(1)(a)) — personalized advertising, where you grant consent via the ATT prompt (iOS) or in-app preference. You may withdraw consent at any time without affecting prior processing.
• Legal obligation (Art. 6(1)(c)) — only when we must respond to a lawful request from authorities.

6. Recipients (with whom we share data)

We do not sell personal data. The categories of recipients are limited to providers strictly required to run the app:

We may disclose data if required by a valid court order or other binding legal process, after verifying the request and notifying you where lawful.

7. International transfers

Some of the recipients above are located outside the European Economic Area (mainly in the United States). Where transfers occur, they are protected by:

• the European Commission's adequacy decision (EU-US Data Privacy Framework) for providers certified under the Framework, including Google LLC;
• Standard Contractual Clauses (SCCs) as adopted by the European Commission, supplemented by additional safeguards where applicable;
• the recipients' own published transfer mechanisms (e.g. Apple's binding corporate privacy commitments).

You can request a copy of the relevant safeguards by writing to mail@macsiem.dev.

8. Retention

9. Your rights (GDPR Art. 15–22)

You have the following rights regarding your personal data:

• Right of access (Art. 15) — confirmation whether we process your data and a copy of it. Most of your data is already on your device; export from the app or write to us for the rest.
• Right to rectification (Art. 16) — correct inaccurate data. Edit data directly in the app.
• Right to erasure / "right to be forgotten" (Art. 17) — delete all data via Settings → "Erase all data", or by uninstalling the app.
• Right to restrict processing (Art. 18) — request a temporary halt; write to us.
• Right to data portability (Art. 20) — Settings → "Export data" produces a JSON / Markdown bundle.
• Right to object (Art. 21) — object to processing based on legitimate interest, especially profiling-style ads. Disable personalized ads in app settings or via system controls.
• Right not to be subject to automated decisions (Art. 22) — Compresser does not make automated decisions with legal or similarly significant effect about you.

To exercise any right, write to mail@macsiem.dev. We respond within 30 days (extendable by 60 days for complex requests, with notice).

10. Right to lodge a complaint (GDPR Art. 77)

If you believe we are processing your data unlawfully, you may file a complaint with a supervisory authority. For Polish residents:

Prezes Urzędu Ochrony Danych Osobowych (PUODO) ul. Stawki 2, 00-193 Warszawa, Poland https://uodo.gov.pl

You may also file a complaint with the supervisory authority of your habitual residence, place of work, or place of the alleged infringement in another EEA country.

11. Children's privacy

Compresser is not directed at children under 13 (under 16 where applicable per local law). We do not knowingly collect personal data from children under that age. If you believe a child has provided us personal data without parental consent, contact us at mail@macsiem.dev and we will delete it promptly.

The "Designed for Families" / "Ages 5+" Apple / Google flags are not set on Compresser — the app is rated for general audiences 13+.

12. Security

• Local-only operations — compression runs entirely in device memory; the original and compressed files never leave your device.
• Transport security — all network calls (ads, IAP, Sentry diagnostics) use HTTPS / TLS 1.2+.
• Minimization — we collect only what is required for the listed purposes.
• No backup of file content to our servers — file metadata (size, format, timestamps) may be retained for in-app history, but file content is not.

No system is 100% secure; please keep your device updated and use strong device locks.

13. App Tracking Transparency (iOS) and Advertising ID

On iOS, before any tracking-grade identifier is used by AdMob, Compresser shows the system App Tracking Transparency prompt. If you decline, Compresser serves only non-personalized ads.

On Android, you can reset or limit your Advertising ID under Settings → Google → Ads. Choosing "Delete advertising ID" stops AdMob from using a personal identifier; non-personalized ads continue to be shown.

14. In-app purchases

Compresser offers the following in-app products through Apple App Store and Google Play: lifetime unlock, optional tip jar, premium annual subscription.

All payment data is handled by Apple Inc. (App Store / iTunes account) or Google LLC (Play Billing). We never see your card number, your billing address, or your full Apple ID / Google account. Apple and Google return only an opaque purchase token and entitlement metadata that we use to unlock features. Subscriptions can be cancelled at any time in iOS Settings → Apple ID → Subscriptions or in the Google Play app → Subscriptions; cancellation rules are governed by Apple / Google.

15. Changes to this policy

We may update this policy as the app, third-party SDKs, or applicable law change. Material changes will be announced in-app and the "Last updated" date at the top will change. Continuing to use Compresser after a change constitutes acceptance of the updated policy.

16. Contact

For privacy questions, exercise of rights, or concerns about this policy:

Maciej Siemiński Email: mail@macsiem.dev

Canonical version of this policy: https://macsiem.github.io/compresser-privacy/ Source: https://github.com/MacSiem/compresser-privacy