Fastivo Privacy Policy
Effective: 24 September 2026 · Version: 1.1
This privacy policy explains what data the Fastivo mobile app
(Android: pl.sakowicz.fastivo) processes and what happens to it.
1. Who is responsible for the app
Fastivo is developed and published by Dariusz Sakowicz (an individual based in Poland), shown on Google Play as the developer of Fastivo.
Privacy contact: d.sakowicz@gmail.com
2. The short version
- Fastivo needs no account or sign-in and has no server of its own.
- Everything you enter in the app (fasts, weight, notes, profile) is stored only on your phone. The developer never receives this data and has no access to it.
- The app contains no analytics or crash-reporting tools.
- The only external services that process data are Google ads (AdMob) and the app store (Google Play, and the App Store for the iOS version) for the "Remove ads" purchase. Health data is never passed to these services.
3. Data stored on your phone
The app keeps the following in a local database on your device:
| Data | Purpose |
|---|---|
| Fasts: start, end, goal, status | fasting timer, history, stats, days in a row |
| Post-fast notes: mood (1–5), what you broke the fast with, reason, your own note | your notes and insights from them |
| Weigh-ins with time of day (morning/evening/other) | weight charts and comparisons |
| Profile (optional): sex, age, height, starting and target weight, activity level, weight-loss pace | BMI, healthy weight range, estimated calorie needs |
| Days in a row and rest days | streak counter |
| Settings: fasting plan, reminders, "ad-free" purchase flag, date you accepted the health notice | app operation |
Some of this is health data (e.g. weight, mood, fasting information). It is processed only on your device, only so the app can work, and the app does not send it anywhere.
Providing any data in the app is voluntary. All profile fields are optional — the app works without them, but won't show the metrics that need them.
4. Data export and import
In Settings you can export your data to a file (JSON). The app opens the system share sheet and you choose where the file goes (e.g. your cloud drive or an email to yourself). The app never sends anything on its own. The file is not encrypted and contains health data — keep it safe and don't share it with others.
Import loads such a file and replaces the data stored in the app.
5. Advertising (Google AdMob)
The free version of Fastivo shows ads served by Google AdMob (Google Ireland Limited / Google LLC): video ads that you choose to watch to earn a reward (e.g. a rest day), and at most one full-screen ad per session. The app shows no banner ads.
To show an ad, the Google Mobile Ads SDK processes — according to Google's documentation — among other things:
- your IP address (which can be used to estimate approximate location),
- your device's advertising ID (Android Advertising ID) and app set ID,
- ad interactions (e.g. views, taps, app launches),
- diagnostic information about app and SDK performance and general device information.
Google uses this data to serve and measure ads, for analytics and for fraud prevention, acting as an independent controller. Details: How Google uses information from sites or apps that use its services and the Google Privacy Policy.
For the collection of data by the ad SDK in the app and its transfer to Google, the app's publisher (section 1) is also a joint controller. The legal basis is your consent (Art. 6(1)(a) GDPR) for personalized ads and, otherwise, the publisher's legitimate interest (Art. 6(1)(f) GDPR): funding the free version of the app and preventing abuse. Personalized ads involve profiling by Google, which happens only with your consent. The app does not make any decisions about you based solely on automated processing that produce legal effects.
Consent (EEA, UK, Switzerland). Before the first ad, the app shows Google's consent form (UMP, IAB TCF standard). If you don't consent to personalized ads, you may receive non-personalized ads (based e.g. on context). You can change your choice at any time in the app: Settings → Ads → Ad privacy settings.
You can reset or delete your advertising ID in Android settings (Privacy → Ads, or Google → Ads).
Ads are limited to content suitable for general audiences (max. "PG" rating).
After you buy "Remove ads", the ad module is never started, so the data described in this section is no longer processed.
6. "Remove ads" purchase
The one-time purchase is handled by Google Play (and the App Store for the iOS version). Payment and billing data are processed by the store under its own privacy policy — the developer never receives your payment details. The app only stores on your phone the fact that the purchase was made, and can restore it from your store account ("Restore purchase").
7. Notifications
Reminders (fasting phases, goal reached, daily weigh-in) are scheduled locally on your phone. The app does not use server push notifications. You can turn notifications off in the app or in your phone settings.
8. Permissions
- Internet and network state — for ads and purchases.
- Advertising ID (AD_ID) — for ads (see section 5).
- Google Play billing (BILLING) — for the "Remove ads" purchase.
- Notifications, run at startup, wake lock, vibration — for local reminders, including after the phone restarts.
The app does not ask for access to your location, contacts, camera, microphone, photos or files. Some libraries add technical permissions (e.g. for app icon badges) that Fastivo does not use to collect any data.
9. iOS version
When Fastivo becomes available for iPhone, the system will ask for permission to track (App Tracking Transparency) before showing ads. The app works fully without it — ads are then non-personalized. The rest of this policy applies unchanged.
10. Retention and deletion
- App data stays on your phone until you delete it. You can delete weigh-ins and the fast in progress in the app; to delete all data, uninstall the app or clear its data in Android settings.
- The app does not create cloud copies of your data. You make your own backup by exporting (section 4).
- Because the developer does not store your data, there is nothing to delete on the developer's side.
- Data processed by Google for ads and purchases is retained according to Google's data retention policy.
11. Security
App data is kept in the app's private storage on your phone, which other apps cannot access. Communication between the ad SDK / the store and Google's servers is encrypted (TLS). Protect your phone with a screen lock — anyone with access to your unlocked phone can see the data in the app.
12. Minors
Fastivo is intended for adults only (18+). Intermittent fasting is not recommended for people under 18. The app is not directed at children and does not knowingly collect children's data.
13. Your rights (GDPR)
You have the right to access, rectify and erase your data, to restrict processing, to data portability, to object and to withdraw consent, and to lodge a complaint with a supervisory authority (in Poland: President of the Personal Data Protection Office, ul. Stawki 2, 00-193 Warsaw, uodo.gov.pl; or the authority in your country).
Right to object. You can object at any time to processing for advertising based on legitimate interest — write to the address in section 1, or buy "Remove ads", after which the ad module no longer runs.
In practice, you are fully in control of the data in the app — you can view, correct, export (portability) and delete it directly in the app. You can change your consent to personalized ads in Settings (section 5). For data processed by Google you can also contact Google directly. For any questions, write to the address in section 1.
Legal bases: you process the app data yourself, on your own device, to use the app; processing for advertising — see section 5 (consent or legitimate interest).
14. Transfers outside the EEA
Google may process data related to ads and purchases outside the European Economic Area, including in the USA, relying on GDPR transfer mechanisms (e.g. the EU-U.S. Data Privacy Framework or standard contractual clauses).
15. Changes to this policy
We will announce significant changes in the app's update notes and on this page. The effective date of the current version is always shown at the top.