Last Updated: July 11, 2026
1. Developer and Contact
WaterKit (the "App") is developed and operated by jusuoli ("we", "us", or "our").
This Privacy Policy applies solely to the App and its related support website.
2. Types of Data We Collect
The App collects only the minimum information necessary to provide its services. All data is stored on your device or in your personal iCloud account, without passing through our servers.
- Profile Information: Username, weight, gender, and activity level that you voluntarily provide to calculate your recommended daily hydration goal.
- Hydration Records: Drink data you log within the App, including beverage type, amount, and timestamp.
- Health Data (HealthKit): With your explicit permission, the App accesses the following data in Apple Health:
- Read & Write: Dietary water intake (dietaryWater), caffeine intake (dietaryCaffeine)
- Read Only: Active energy burned (activeEnergyBurned), body mass (bodyMass), biological sex (biologicalSex)
- Preferences: Your app preferences (units, reminder times, theme, etc.) stored locally via UserDefaults.
The App does not collect: email addresses (unless you contact us), phone numbers, location data, device identifiers, advertising identifiers (IDFA), usage analytics, or crash logs.
3. Purposes of Data Processing
Your data is used solely for the following purposes:
- Tracking and displaying your daily hydration progress and goal achievement
- Calculating personalized daily hydration goals based on your weight, gender, and activity level
- Sending local notifications to remind you to drink water
- Generating statistics and trend insights about your drinking habits
- Syncing data across your devices via iCloud
- Writing hydration data to Apple Health to maintain consistent records
- Displaying today's hydration progress on widgets and Apple Watch
4. Data Storage and Security
The App uses the following methods to store and protect your data:
- Local Storage: All data is stored on your device using SwiftData, protected by iOS Data Protection encryption.
- iCloud Sync: If you enable iCloud Sync, data is encrypted and synced to your personal iCloud account via CloudKit. The synced data is encrypted and transmitted only between your Apple ID devices, without passing through our servers.
The App does not use any third-party servers to store your data. We take reasonable technical and organizational measures to prevent unauthorized access, disclosure, modification, or destruction.
5. Third-Party Services
The App uses only the following Apple platform services:
- Apple HealthKit: Reads and writes health data. Health data is never shared with third parties.
- Apple StoreKit: Processes subscription and in-app purchase transactions. We do not handle your payment information.
The App does not use any advertising SDKs, analytics tools, crash reporting services, or third-party tracking technologies.
6. Notifications
The App uses local notifications to send hydration reminders. These notifications are processed and scheduled entirely on your device without involving remote server pushes. You can disable or manage notification permissions at any time in System Settings → Notifications.
7. Data Retention and Deletion
Your data is retained as long as you use the App. You can delete your data at any time by:
- Deleting individual drink records within the App
- Clearing all records in the App's settings
- Uninstalling the App, which removes all local data from your device
- Managing or deleting iCloud synced data through your iCloud settings
After uninstalling the App, local data is immediately deleted. iCloud data will be retained or deleted according to your iCloud storage settings.
8. Your Rights
Under the General Data Protection Regulation (GDPR), you have the following rights regarding your Personal Data:
- Withdraw consent: You have the right to withdraw consent where you have previously given your consent to the processing of your Personal Data.
- Object to processing: You have the right to object to the processing of your Data if the processing is carried out on a legal basis other than consent.
- Access your Data: You have the right to learn if Data is being processed by us, obtain disclosure regarding certain aspects of the processing, and obtain a copy of the Data undergoing processing.
- Verify and seek rectification: You have the right to verify the accuracy of your Data and ask for it to be updated or corrected.
- Restrict processing: You have the right to restrict the processing of your Data. In this case, we will not process your Data for any purpose other than storing it.
- Have your Data deleted: You have the right to obtain the erasure of your Data from us.
- Data portability: You have the right to receive your Data in a structured, commonly used and machine readable format and, if technically feasible, to have it transmitted to another controller without any hindrance. To export your data, use the in-app data export feature, or submit a request to us via email. We will provide it within one month.
- Lodge a complaint: You have the right to bring a claim before your competent data protection authority.
Any requests to exercise these rights can be directed to us through the contact details provided in this document. Such requests are free of charge and will be answered as early as possible and always within one month. To contact us, email jusuoli2006@163.com.
9. Notice for European Union Users
If you are located in the European Union or European Economic Area, please note the following:
- The legal basis for processing your personal data is your consent: the profile information you voluntarily provide, the hydration records you actively log, and your authorization for HealthKit access and iCloud sync.
- The App does not collect or transmit your personal data — it has no servers of its own. Your data is stored on your device or in your personal iCloud account, which we cannot access.
- If you enable iCloud sync, cross-border data transfer is managed by Apple under iCloud terms. See Apple's Privacy Policy. You can manage or disable iCloud sync at any time in system settings.
- The App complies with the GDPR. Since we do not collect your personal data, your data remains under your control at all times.
10. Children's Privacy
The App is not directed at children under the age of 9. We do not knowingly collect personal information from children under 9. If you believe we have inadvertently collected data from a child, please contact us at jusuoli2006@163.com and we will promptly delete it.
11. Changes to This Policy
We reserve the right to modify this Privacy Policy at any time. In the event of material changes, we will notify you by updating the "Last Updated" date on this page. We recommend that you review this page periodically for any changes. If changes affect processing activities based on your consent, we will obtain fresh consent from you.
12. Contact
If you have any questions about this Privacy Policy or data processing, please contact: