Is Mathe-Trainer safe?

Mental arithmetic practice on a tablet, for children from their first school year. The app measures the time to the correct answer and turns it into a learning curve and leaderboards, where several children on the same device compete with each other. The interface is in German only. It runs entirely offline. No account, no ads, no analytics and no internet permission - the app cannot send anythin…

Developer: Christoph Bayer
Category: Science & Education
Earliest archived version: 01 Oct 2026
License: GPL-3.0-or-later (per F-Droid metadata)

02 / Package identity

Technical fingerprint

Application IDcom.chrbayer.mathe_trainer

Latest APK SHA-256d88bd5a5db1659e9eb26f7a5ba7152db2027591ba4c761495ecb917ab62870f0

Signing certificate7E:85:B3:25:8C:FD:28:05:92:78:88:7F:77:1D:0B:E0:FE:B7:B8:1C:81:43:90:31:29:F8:52:99:37:A6:11:A1

MIN ANDROID24TARGET36ARCHITECTUREx86_64

03 / History

Archive history

2 versions in WIKI archive: earliest 2.13.9 (01 Oct 2026), latest 2.15.1 (02 Oct 2026).

No change in android.permission.* between 2.13.9 and 2.15.1.

04 / Version archive

Documented releases

2 TOTAL

VersionReleasedAndroidArchitecture

2.15.102 Oct 202624+x86_64→2.13.901 Oct 202624+x86_64→

05 / Safety & access

Safety verdict

Authentic — file hash matches the source indexNo ads or tracking flagged by the source

IntegritySHA-256 verified vs source

SourceOpen-source · fdroid

Permissions1 declared · 0 sensitive

Signaturepresent

Anti-featuresNo known anti-features

Sensitive accessNo sensitive permissions

Declared permissions

com.chrbayer.mathe_trainer.DYNAMIC_RECEIVER_NOT_EXPORTED_PERMISSION

Tracker status: Not assessed by WIKI for Android.

06 / Sources

Evidence ledger

Each entry is a captured public reference backing this record.

RepositorySource package page↗Source codeSource repository↗