Privacy Policy — Double Digits
Last updated: October 13, 2026
Summary
The developer of this app does not collect personal information that identifies you, such as your name or email address. Your practice records are stored only on your device. The developer operates no servers.
To improve the app, it uses two analytics services: Google Analytics for Firebase from Google and Microsoft Clarity from Microsoft. Usage information (such as which screens were viewed and whether a practice run was completed), along with recordings of the app's screens and tap positions, is sent to Google and Microsoft. See "Usage analytics" below for details.
This app contains no advertising or crash-reporting software. No account is required.
Information stored on your device
The app stores your practice records (such as your completion times and their history, the dates you practiced, and your practice settings) on your device only. None of this leaves your device, and the developer has no means of viewing it. Deleting the app deletes all of it.
Usage analytics
To understand how the app's features are used and to improve it, this app uses the following two analytics services.
Google Analytics for Firebase
This app uses Google Analytics for Firebase ("Firebase Analytics"), provided by Google.
Through Firebase Analytics, the following is sent to Google:
- In-app activity: screens viewed; practice runs started, completed, or quit; the number chosen; the number of problems; completion time; whether a best time was set; and how many problems were answered before quitting
- Usage such as app launches and time spent in the app
- Device and environment information: device model, OS version, app version, language setting, and approximate region (country/region level, estimated from your IP address)
- An identifier issued for each installation of the app (app instance ID)
Your name, email address, Game Center nickname, and the practice records themselves are not sent. The app is configured not to collect the advertising identifier (IDFA / Advertising ID), and the information sent is not used for advertising or tracking.
The developer receives only aggregated statistics from Google. Google's handling of this information is governed by the Google Privacy Policy. For how Firebase handles data, see Privacy and Security in Firebase.
Microsoft Clarity
This app uses Microsoft Clarity ("Clarity"), provided by Microsoft. To find where people get stuck, Clarity records how the app is used in the form of session recordings.
Through Clarity, the following is sent to Microsoft:
- Recordings of the app's screens (session recordings) and the positions of taps, scrolls, and other interactions
- The names of screens viewed, and the fact that a practice run was started, completed, or quit
- Device and environment information: device model, OS version, app version, screen size, and approximate region (estimated from your IP address)
- An identifier that Clarity issues for each device
The app's screens show only arithmetic problems, the numbers you enter, times, and practice records. No personal information such as your name appears on screen, so none is included in the recordings. However, the Game Center leaderboard screen opened from the app (displayed by Apple) may appear in a recording, in which case Game Center nicknames may be included.
The developer views the recordings and aggregated results in the Clarity dashboard. Microsoft's handling of this information is governed by the Microsoft Privacy Statement.
About Game Center
This app offers leaderboards through Game Center, a service provided by Apple.
This feature is optional. If you decline to sign in to Game Center, every practice feature of the app remains fully available; only the leaderboard feature is hidden.
If you do use Game Center, the following is sent to Apple:
- Your completion time when you finish a practice run
- Your Game Center nickname (not the real name on your Apple Account)
The submitted time and nickname are visible to other players on the leaderboard. This is inherent to how a ranking feature works.
Game Center is an Apple service, and Apple's handling of this data is governed by the Apple Privacy Policy. The developer does not receive information from Apple that identifies you as an individual.
What this app does not do
For clarity, this app does not:
- Collect your name, email address, phone number, or postal address
- Access your location
- Access your camera, microphone, contacts, or photos (it requests no permissions at all)
- Display advertising, or collect or use the advertising identifier (IDFA / Advertising ID)
- Track you across other companies' apps or websites
- Sell information to third parties (apart from what is sent to Apple, Google, and Microsoft as described above, nothing is shared with third parties)
Children's privacy
This app is intended for arithmetic practice and may be used by children. As described above, the app collects no personal information that identifies you, so nothing additional is gathered regardless of age. The information sent for usage analytics (Firebase Analytics / Clarity) is likewise limited to what is described above, regardless of age.
Note that the Game Center leaderboard displays your nickname to other players. If a child uses this app, we ask that a parent or guardian review the Game Center nickname setting, and decide whether to sign in to Game Center at all.
Game Center can be restricted from the device under Settings > Screen Time > Content & Privacy Restrictions.
Changes to this policy
This policy may change as features are added to the app. If a significant change is made, the "Last updated" date above will be revised.
Contact
For questions about this policy or about privacy in this app, please contact: