# Privacy Policy — Which Costs More
**Last updated:** October 8, 2026
**App:** Which Costs More (`com.mazellan.whichcostsmore`)
**Developer:** Selçuk Korkusuz
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## Overview
Which Costs More is a price-guessing game. You can play without creating an account and
without giving us your name, email address or phone number. This policy explains what
data the app handles, why, and what you can do about it.
## Data stored only on your device
- **Game progress:** your best streak per category, your daily challenge best, and a count
of games played (used only to decide when to show the App Store rating prompt)
- **Settings:** language, sound on/off, optional leaderboard nickname
- **Catalog cache:** product names, prices and categories downloaded for the game
This data stays on your device and is removed when you uninstall the app.
## Data sent to our servers (Google Firebase)
### Community leaderboard
When you set a new best streak in a category, the app automatically sends that score to
the community leaderboard. To do this it uses **Firebase** (Google Cloud) to:
- create an **anonymous account** — a random user ID with no email, password or name
- store your **best streak**, its **category** and **game mode**, a **display name**
(the nickname you chose in Settings, or an automatic label such as "Player a1B2c3"),
and the **time** of the last update
Leaderboard entries — display name and score — are visible to other players. Do not use
your real name as a nickname if you do not want it shown. Daily challenge scores are not
sent to the leaderboard.
### Product catalog and images
The app downloads product names, approximate prices and photos from **Firebase Firestore**
and **Firebase Storage**. This is game content, not information about you.
### Technical data
As with any internet service, Google's servers receive technical information needed to
deliver these requests, such as your IP address and basic device/app information. We do
not use it to identify you and we do not combine it with other data.
## What we do not collect
- No name, email address, phone number or contacts
- No location
- No photos, microphone or camera access
- No advertising identifiers; no ads and no cross-app tracking
- No analytics or behavioural profiling
- No payment or financial information
We do not sell or share your data with third parties for their own purposes.
## How we use data
- To run the game and keep the product catalog up to date
- To show leaderboard rankings
- To remember your settings and scores
## App Store rating prompt
The app may occasionally ask you to rate it using Apple's standard rating dialog. That
dialog is provided by Apple; we do not see whether or how you respond.
## Third-party services
| Service | Purpose |
|---------|---------|
| Google Firebase (Authentication, Firestore, Storage) | Anonymous accounts, leaderboard, catalog and image hosting |
| Apple (App Store) | App distribution and the optional rating dialog |
Product photos come from Pexels and from public-domain / CC0 sources. They are processed
by us and served from Firebase Storage; current versions of the app do not contact those
sources.
Firebase privacy information: https://firebase.google.com/support/privacy
## Data retention
- **On-device data:** until you uninstall the app or clear its data
- **Leaderboard entries and anonymous account:** until you delete them in the app (see
below) or we remove them (for example, entries with offensive nicknames or obviously
invalid scores)
## Your choices and rights
In **Settings** you can:
- change or clear your nickname
- **Delete my community data** — permanently removes your leaderboard entries and your
anonymous account from our servers
Because we do not know who you are, the in-app delete button is the fastest way to remove
your data. You can also email us and we will help. Depending on where you live (for
example under the GDPR or the Turkish KVKK), you may have rights to access, correct,
delete or object to the processing of your personal data, and to complain to your data
protection authority.
## Legal basis
We process leaderboard data to provide the game's leaderboard feature that you use
(performance of the service / legitimate interest in running the game).
## Children
The app is not directed at children under 13 and we do not knowingly collect personal
information from children. The app has no chat, no ads and no purchases.
## International transfers
Data is processed on Google's servers, which may be located in the United States and
other countries.
## Changes
We may update this policy. The "Last updated" date at the top will change, and significant
changes will be noted in the app's release notes.
## Contact
**mazellangames@gmail.com**