Privacy Policy of the «Health Diary» App

Last updated: 21 October 2026.
Developer: an individual distributing the app under the «Толстый кот» / Fat Cat Apps brand. Contact: info@fatcatss.ru.

The developer of the Health — Well-being Diary app is Sergey Grodzitsky (the Tolstiy Kot / Fat Cat Apps brand). Contact: info@fatcatss.ru.

1. In short

• By default, all your records (blood pressure, pulse, glucose, temperature, weight; your cycle diary with basal temperature; medications — schedules and intake log; steps; the food diary) stay only on your device until you turn on cloud sync (“Health Online”, §4 — off by default).
• Camera-based recognition of numbers on your device's display runs on the device by default and needs no network.
• Optionally, you can enable cloud recognition ("Use AI" in Settings, off by default). Then a photo of the device's display or of a meal (or a product name as text) is sent to our server in Russia and forwarded to an AI provider to read the numbers or estimate nutrition values. The request content contains your health indicators — enable it deliberately.
• No ads and no third-party ad networks; analytics is limited to anonymous launch statistics, which you can turn off (see below).

2. What data is processed

• Measurements (blood pressure, pulse, glucose, temperature, weight) — on your device only; never transmitted.
• Cycles diary (period days, observations, basal temperature) — on your device only.
• Steps (the phone's sensor, daily totals, goal) — on your device only; the activity-recognition permission is granted only when you explicitly turn step counting on.
• Food diary (meals: name, grams, nutrition values; your personal product base) — on your device only.
• Cloud request content (only when cloud recognition is enabled): a compressed photo of the device's display or of a meal (up to 800 px), or a product name as text, is sent to api.fatcatss.ru to read the numbers or estimate nutrition values. It contains your health indicators or information about your food — a special category of personal data processed solely on your explicit consent (turning the option on). It is used only for recognition/estimation and is not stored on our server.
• Device identifier (a random UUID created by the app): sent with each request for abuse protection and rate limits. It contains no name or contact details and is never linked to them; in server logs it is stored as a hash.
• Server technical logs (date, AI model, status, duration, hashed device identifier) — without photo content and without recognised values.
• App updates: the app may check for updates — at most once a day it downloads a small file from fatcatss.ru containing only the latest version number and a download link. No information about you or your device is sent with this check; the server only sees a routine technical request.
• Anonymous launch statistics. Each time the app starts, it sends the developer's server three impersonal fields: the app's name and version and the device's country (e.g. "RU"). The statistics contain and store no device or user identifiers, and no IP address is stored; it is impossible to single out any individual from this data. You can turn the collection off in Settings ("Anonymous statistics").
• Park announcements. At most three times a day the app anonymously requests short informational texts by Fat Cat Apps (e.g. news about the app park) from fatcatss.ru and may show one of them; the text language follows the app language. The request carries no data about you or your device, and shows are not counted; following a link inside an announcement (if any) happens only on your tap. Without network no announcements are shown and the app works in full.

3. Third parties and cross-border transfer

With cloud recognition enabled, the request content (a photo or a product name) is processed by the AI providers used by the developer: primarily Z.AI (Zhipu AI) — processed in real time without storing (according to the provider's documentation), infrastructure in Singapore; if it is unavailable — Yandex AI Studio (Yandex LLC, Russia) under its privacy policy. Both providers process the content solely to read the numbers or estimate nutrition values on your request and do not use it for advertising. Z.AI processing is a cross-border transfer of personal data; by enabling cloud recognition you consent to such transfer. Our application servers are located in the Russian Federation.

Apps by Fat Cat Apps installed on the same device can exchange service events with each other (for example, about a finished walk or a completed task) directly, without sending data over the internet. The feature is on by default; you can turn it off in the settings of the respective app.

3.1. Recognition with your own key (only when you enable it)

In Settings (AI → Measurement recognition → "Paid AI") you can enable the mode with your personal API key of a chosen provider (Z.ai, OpenAI, Google Gemini, OpenRouter — list in the app). In this mode a photo of the device's display is sent directly to the chosen provider with your key, bypassing our server: we receive neither the photo nor the key. The key is stored only on your device. The provider processes the photo under its own privacy policy (published on its website); the place of processing and terms depend on the chosen provider. The photo may contain other people's data — crop it so that third-party data stays out of the frame. Enabling the mode is a separate consent (a dialog when entering the key); turning it off or changing the provider restores the previous mode.

4. Storage and deletion

• Measurements and diaries are deleted when you uninstall the app or via backup/restore that you control (a JSON file on your device).
• Cloud sync ("Health Online", only when you enable it): when sync is on, your readings (blood pressure with pulse, glucose, temperature, basal temperature, weight), your cycle diary (cycle dates and characteristics, observations, basal temperature entries linked to the cycle), medications (medication names and schedules, intake marks), daily steps, the food diary and your product base, profile name and height are transferred to and stored on our server api.fatcatss.ru (Russia), tied to your account — so you can open and edit them on fatcatss.ru (including in “Health Online”) and move them between devices. This is health data — a special category of personal data (Art. 10 of 152-FZ); enabling sync is your explicit consent to its cloud processing — this includes information about your cycles and medications. If sync was enabled earlier, the app will additionally ask for your consent to upload the cycle diary and medications — without it, these sections remain on your device only. Data is stored while your account exists; individual records are deleted in the web cabinet (deletions propagate to the app), deleting the account removes all synced data. Turning the sync toggle off stops the exchange; earlier copied data stays in the cloud until deleted. Sync logs contain facts only (date, types, counters) — no record content. Sync talks only to our server in Russia; no AI providers or third parties are involved.
• Photos and request texts are processed at the moment of the request and are not stored on the server: neither on disk nor in logs. Server logs contain only technical metadata (date, model, status, duration, hashed device identifier) — for no longer than 30 days.
• The device identifier is stored on your device; reinstalling the app resets it.

4.1. Medications

Medication reminders (the “Medications” section): medication names and schedules, intake marks. By default this data stays only on your device: nothing is sent to the server unless cloud sync (§4) is enabled. Included in the user backup (a JSON file you create and keep). Reminders fire locally via exact Android alarms with your separate permission. Medication data is sensitive: the app is not a medical device, does not diagnose and does not give medical advice.

5. Not a medical device

The app is a diary for recording and visualising your readings. It does not measure anything itself, is not a medical device, does not make diagnoses and does not prescribe treatment. Recognised values may contain errors — verify them before saving. Consult a doctor for medical decisions.

6. Children

The service is not intended for persons under 12 and does not knowingly collect their data.

7. Your rights and contacts

Withdraw consent by turning "Use AI" off in Settings. Questions and requests: info@fatcatss.ru; complaints — to Roskomnadzor or a court.