Privacy Policy — Water Tracker

Last updated: August 16, 2026 · Deutsch

Water Tracker (package com.hydroaquatracker.app) is a hydration-tracking app that works entirely on your device. This policy explains what data the app handles, who is responsible for it, and what rights you have.

Controller

Ersal Arslan
Valencia, Spain
Email: hydrotracker@proton.me

No data collection by the provider

The app has no backend server of its own, requires no user account, includes no analytics, advertising, or crash-reporting SDKs, and does not request the INTERNET permission. The provider therefore never receives your data at any time.

Your data leaves your device only in cases you trigger yourself, and only to a recipient you choose. There are exactly two such cases, both described in detail below:

• the CSV export, if and when you share the exported file (see "Data export, import and sharing"); and
• the app rating dialog, if and when you choose to use it (see "App rating dialog (Google Play In-App Review)").

Beyond these two cases, no app data leaves your device. Should a future version introduce any further functionality that transmits data (e.g. an optional sync to your own paired devices), this privacy policy will be updated accordingly beforehand and published with a new "last updated" date.

Who is responsible for your data

All data you enter into this app is stored only on your own device. The provider never receives, sees, or processes this data — comparable to a notes app or an offline spreadsheet.

The provider's role is limited to supplying the software that performs this local storage and calculation on your device and on your behalf. It determines neither the purposes nor the means of any processing of your individual entries, and it has no technical means of accessing them. In the provider's assessment, it is therefore not a controller (Art. 4 No. 7 GDPR) in respect of the content you enter.

In addition, where you use the app exclusively for personal or household purposes, your own processing of your data may fall under the household exemption (Art. 2(2)(c) GDPR). This exemption applies to you as the person processing the data; the provider does not rely on it for its own position.

Because the assessment above could be judged differently, the provider sets out in the "Legal basis" section below, in the alternative, the legal bases on which it would rely should it nonetheless be regarded as a controller. Even in that case it has no access to the locally processed data at any time, so it cannot itself act on that data.

Legal basis

To the extent the provider should be regarded as a controller for any processing, it relies, in the alternative, on the following legal bases:

• Provision of the app's core functions (local storage and calculation of your entries) — Art. 6(1)(b) GDPR (providing the function you requested) and Art. 6(1)(f) GDPR (legitimate interest in a functioning app).
• Health-related entries (weight, height, gender, activity level) — Art. 9(2)(a) GDPR. You enter this data during initial setup so that the app can calculate a suggested daily goal for you. On the screen where you enter it, the app tells you what it is used for and that it stays on your device; by confirming that screen you give your explicit consent to this local processing. You can change these values at any time under Profile, and remove them together with all other app data via "Delete all data" in settings — which withdraws that consent with effect for the future.
• Personalized reminders ("Smart Mode") — Art. 6(1)(a) GDPR (consent through activation of the feature), withdrawable at any time with effect for the future.
• App rating dialog (Google Play In-App Review) — Art. 6(1)(a) GDPR (consent, given by your choosing to use the dialog that is offered to you) and Art. 6(1)(f) GDPR (legitimate interest in feedback on the app). See the dedicated section below.

What is stored, and where

All app data — your drink log, daily goals, weight, height, gender, activity level, an optional profile photo, and app preferences (theme, units, reminder settings) — is stored locally on your device, using a local database, local app preferences, and local app storage. It is not shared with third parties and not backed up to any cloud service.

Some of this data (e.g. weight, height, activity level, drink log) may be considered health data under Art. 9 GDPR. It is processed exclusively on your device and is never accessible to the provider, so in the provider's assessment no obligations under Art. 9 arise for it — see "Who is responsible for your data" above. To the extent such processing should nonetheless be attributable to the provider, it relies on your explicit consent under Art. 9(2)(a) GDPR (see "Legal basis").

Uninstalling the app permanently deletes this data. You can also delete all stored data at any time from within the app's profile/settings screen.

Notifications permission

On Android 13 and later, the app requests the POST_NOTIFICATIONS permission. This is used solely to show local hydration reminder notifications (e.g. "time to drink water") that are scheduled and generated entirely on your device. No notification content is generated by or sent to any server.

Personalized reminders ("Smart Mode")

If enabled, Smart Mode reviews your drinking patterns from the last 14 days, entirely on your device, to time reminders for hours you tend to forget to drink. This is a local calculation only: it has no legal effect on you, is not shared with anyone, and can be turned off at any time in settings.

Data export, import and sharing

The app lets you export your own drink history as a CSV file so you can share or back it up yourself. This export is created locally and only leaves the device if you explicitly choose to share it (e.g. via email or another app of your choosing). Once you share the exported file with another app or service, that app or service's own privacy policy applies to the data it receives — the provider of Water Tracker has no involvement in or control over that transfer.

You can also import a CSV file back into the app. The app reads only the single file you select in your device's file picker, processes it locally, and stores the resulting entries in the same local database as all your other data. Nothing is uploaded, and the provider receives nothing in this process.

App rating dialog (Google Play In-App Review)

After you have reached your daily goal on several consecutive days, the app may offer you Google's standard in-app rating dialog. The dialog itself is displayed and handled entirely by the Google Play Store app on your device, not by Water Tracker.

When this dialog is requested and when you use it, Google receives the related data as its own controller — in particular the fact that a rating was requested for this app, your Google Play account, and any rating or review text you choose to submit. Google may publish a review you submit in the Play Store under your Play profile name. Water Tracker does not read your rating, does not receive your review text, and cannot link a review to your app data.

The dialog is only ever offered, never forced: you can dismiss it, and no rating is transmitted unless you actively submit one. Because Google Ireland Limited and Google LLC (USA) are involved in operating the Play Store, this can involve a transfer to the USA; Google states that it safeguards such transfers by means of the EU-US Data Privacy Framework and Standard Contractual Clauses. See Google's Privacy Policy for details.

Recipients and international data transfers

The provider itself does not transfer any data from this app to any recipient or to any third country, because the provider never receives this data in the first place. Data reaches a third party only in the cases you trigger yourself, described above: the recipient you choose when sharing a CSV export, and Google in connection with the app rating dialog and with the operation of the Play Store.

This privacy policy page itself is hosted on GitHub Pages (GitHub Inc., USA). Loading this page causes GitHub to process technical access data (e.g. your IP address, server log data) as part of its hosting infrastructure, independent of the app. The legal basis for this is Art. 6(1)(f) GDPR (legitimate interest in the secure and reliable delivery of this page). As GitHub Inc. is based in the USA, this involves a transfer to a third country, which is safeguarded by the EU-US Data Privacy Framework and, in addition, by Standard Contractual Clauses. See GitHub's Privacy Statement for details.

Distribution via Google Play

If you installed this app from the Google Play Store, Google collects certain installation, device, and diagnostic data as part of operating the store, independent of this app. See Google's Privacy Policy for details.

Your rights

Because your data is stored only on your device and the provider has no access to it, you exercise your rights directly within the app:

• Access / portability (Art. 15, 20 GDPR) — view your data in the app, or use the CSV export feature.
• Rectification (Art. 16 GDPR) — edit your profile, goals, and entries directly in the app.
• Erasure (Art. 17 GDPR) — delete individual entries, or use "Delete all data" in settings to remove everything.
• Restriction of processing (Art. 18 GDPR) — because processing happens only locally, you achieve a restriction by disabling the relevant feature or deleting the data.
• Objection (Art. 21 GDPR) — disable Smart Mode or notifications in settings, or uninstall the app at any time.
• Withdrawal of consent (Art. 7(3) GDPR) — any consent you have given can be withdrawn at any time with effect for the future: disable Smart Mode in settings, use "Delete all data" to remove your body data, or simply dismiss the rating dialog. Withdrawal does not affect the lawfulness of processing carried out before it.

You also have the right to lodge a complaint with a data protection supervisory authority, in particular in the EU member state of your residence, place of work, or place of the alleged infringement (Art. 77 GDPR). As the provider is based in Spain, the Spanish data protection authority (Agencia Española de Protección de Datos, AEPD, www.aepd.es) is competent; you may, however, also contact the authority where you reside.

Children's privacy

The provider does not knowingly collect any information from children, or from anyone else, because the provider does not collect or have access to any information processed by this app (see "Who is responsible for your data" above). The age-related requirements of Art. 8 GDPR, which concern a provider's collection of children's data, are therefore not triggered.

Changes to this policy

If this policy changes, the updated version will be published at this same URL with a new "last updated" date.

Contact

Questions about this policy, or requests relating to your rights, can be sent to hydrotracker@proton.me.