Privacy Policy
PlusC ("the App") is a math learning app provided by an individual developer ("the Developer"). This policy explains what information the App handles and why.
1. Information We Collect
Using the App without signing in
Study features and local (pass-and-play) battles require no account. In this case, all learning history, statistics, and achievements are stored only on your device and are never sent to the Developer's servers.
If you create an account (ranked battles & friends)
Ranked online battles and the friends feature require an account via Sign in with Apple. We then collect and store:
- Account information: the email address provided by Sign in with Apple (a relay address if you choose "Hide My Email") and a user identifier
- Profile information: display name (nickname) and friend code
- Match data: battle results, rating, rank tier, season history, and records needed to cross-verify results between players
- Friend relationships: your friend list and friend request status
- Reports: the content of cheating reports you send or receive
Online battle connectivity
Real-time online battles use Apple's Game Center. Information handled by Game Center is governed by Apple's Privacy Policy.
2. How We Use Information
- Matching ranked battles, computing ratings, and managing tiers and seasons
- Server-side verification of match results and anti-cheat protection
- Providing the friends feature
- Account management and deletion
3. Information We Do NOT Collect
- No location, contacts, photos, or browsing data
- No ads, no ad-related data collection, no sale or sharing of data, no tracking
- No third-party analytics SDKs
4. Storage and Management
Collected information is stored in Firebase (Google LLC; data center region: Tokyo). Firebase's data handling is governed by Google's Privacy Policy. The Developer does not share collected information with third parties except as required by law.
5. Deleting Your Data
You can delete your account and all associated server data (profile, match history, friend relationships, etc.) at any time from Settings → Delete Account in the App. On-device learning data is removed by deleting the App.
6. Children
The App is a learning app suitable for a wide range of ages, including students. We collect only the minimal personal information listed above, and the only information visible to other users is your display name.
7. Changes to This Policy
Changes will be announced on this page.
8. Contact
Please contact the Developer via the contact information listed on the App's App Store page.