Privacy policy

Last updated: 18 October 2026

Waifu Hydration ("the app") is made by MonstersGhost, an independent developer. This policy explains what the app does with your information. Short version: your water log lives on your phone, not with us. The free app shows a small banner ad from Google, and Google's ad software collects some data about your device to do that. Waifu Hydration Pro removes the ads and that data collection. Details below.

Who is responsible

MonstersGhost, an independent developer based in Kuwait, is responsible for the app and this policy. Contact: waifuhydration.app@gmail.com. For the ad data described below, Google is also responsible, as a separate controller, for how it uses that data.

What the app stores

• What you log: how much you drink, when, and any details you add
• Your settings and preferences, such as glass size, daily goal, units (metric or US), reminder times or interval, quiet hours, precise timing and appearance (System, Light or Dark)
• Your time with your character, such as your progress together and the messages she has left you
• Reminder scheduling details, including your time zone, so reminders arrive at the right local time
• What you've bought, such as Pro, so it keeps working offline

Everything you log, set or unlock stays on your phone. The app has no account and no servers of its own, and tracking and reminders work offline. New features that work only on your phone follow the same rule. Anything that would share your data with another app or service will be optional, off until you turn it on, and described in this policy before it's released.

Ads

The free app shows a banner ad from Google AdMob. To show and measure ads and to prevent fraud, Google's ad software in the app automatically collects and shares:

• your IP address, which can show your approximate location
• how you use the app, such as app launches and taps on ads
• diagnostics, such as app performance
• device identifiers: your Android advertising ID and app set ID

This data goes to Google, encrypted in transit, and is used for advertising, analytics and fraud prevention. We don't receive it; AdMob only shows us overall ad statistics. Nothing you log, set or unlock in the app is ever part of it. Ads are limited to content rated for general audiences or parental guidance.

If you're in the EEA, the UK or Switzerland, the app asks for your consent before personalised ads are shown, and you can change your choice anytime under Settings > About > Ad privacy choices. You can reset or delete your advertising ID in your phone's settings.

Personalised ads mean Google builds a picture of your interests (profiling). In the EEA, the UK and Switzerland that only happens with your consent. The app makes no automated decisions about you that have legal or similarly significant effects.

If you have Pro, the app never starts Google's ad software, so none of this data is collected.

How Google uses this information: https://policies.google.com/technologies/partner-sites

Purchases

The app offers optional one-time purchases, such as Waifu Hydration Pro, which removes the ads. Google Play handles the payment, your payment details and refunds; we never see your card or payment details. Google Play tells the app what you own (the product, the purchase state and a purchase token), and the app checks that record on your phone and remembers it there. We don't receive your purchases or keep them on a server. Google's privacy policy applies to the payment: https://policies.google.com/privacy

Google Play

Some features come from Google Play itself, such as app updates, rating the app and downloading content you've bought. Google Play handles these: for example, it uses your device details and app version to deliver the right download, and a rating you leave is posted on Google Play. Google's privacy policy applies to them.

Legal bases (EEA, UK and Switzerland)

• Personalised ads, and storing or reading ad information on your device: your consent. You can withdraw it anytime under Ad privacy choices.
• Limited, non-personalised ads, ad measurement and fraud prevention: legitimate interests in keeping the free app running and ads honest, or your consent where the law requires it.
• Purchases: to deliver what you bought.

International transfers

Google may process ad and payment data outside your country, including in the United States. Google uses legal safeguards for this, such as the EU-US Data Privacy Framework and the European Commission's standard contractual clauses.

How long data is kept

Data on your phone stays until you delete it (see below). We don't keep any data from the app ourselves. If you email us, we keep your messages as described under Contact. Google keeps ad and payment data according to its own policies.

Your rights

Depending on where you live, including under the GDPR, you can ask to access, correct or delete your personal data, restrict or object to its use, or get a copy of it, and you can withdraw consent at any time. We don't hold any data from the app, so most requests are answered by Google: see https://policies.google.com/privacy for how to reach them. You can also email us and we'll help. If you're in the EEA, the UK or Switzerland, you can complain to your local data protection authority.

US state privacy

Some US states, such as California, give residents rights over the use of their personal information for targeted advertising, which their laws may call "selling" or "sharing". We don't sell your data for money. In the free app, Google's ad software may use the data described under Ads to show personalised ads. Where the app shows Settings > About > Ad privacy choices, you can opt out there. You can also reset or delete your advertising ID in your phone's settings, or get Pro, which turns the ad software off. To use your other rights, email us.

Backups

Android backup is on by default, and the app doesn't exclude its data from it. Depending on your phone and settings, Android may copy the app's data to your Google account's backup or move it to a new phone during setup. We never receive these backups. You can manage backup in your phone's settings.

Deleting your data

Clearing the app's storage or uninstalling it deletes its data from your phone. A copy may remain in your backup or on another phone, and reinstalling may restore it. You can manage backups in your phone's settings. Pro stays yours after a reinstall: use Restore purchases on the Pro screen. Data collected by Google's ad software is handled by Google; see the link above.

Permissions

• Notifications: to show hydration reminders and other notifications from the app. You can turn them off in the app's settings or your phone's settings.
• Alarms and reminders (optional): lets reminders arrive exactly on time.
• Vibration: lets reminders vibrate.
• Run at startup: restores your reminders after the phone restarts.
• Internet and network state: to load ads and, where required, the consent message, and to check purchases with Google Play.
• Advertising ID: lets Google's ad software read your resettable advertising ID.
• Keep awake and background tasks: used by Google's ad software for short background work.
• Google Play billing: lets you buy Pro through Google Play.

Data collection and sharing

The app doesn't send your water log, settings or progress to us or to anyone else. It has no analytics or crash-reporting code of its own. If you've allowed your phone to share usage and diagnostics data with Google, Google Play may show us crash and performance reports, such as the phone model, Android version and where the app crashed. These reports don't include your name, contact details or water log. Google's ad software collects and shares the data described under Ads, and Google Play handles purchases as described under Purchases.

Children

The app isn't directed at children under 13.

Changes

If the app ever changes how it handles data, this policy will be updated before that version is released, and the date above will change.

Contact

Questions about this policy or your data: waifuhydration.app@gmail.com

If you email us, we receive your email address and whatever you write. We use them only to reply to you and keep them in our inbox for as long as they help us do that, for example if you write again. You can ask us to delete them at any time.