Last updated: 1 August 2026
Lernen does not collect, transmit, or store any personal information. There is no account, no analytics, no advertising, and no server.
That is the whole policy. The rest of this page only explains why it can be that short, and what the app does on your own device.
Everything. Lernen keeps your progress — the words you've learned, review schedules, XP, streaks, and finished lessons — in the app's private storage on your device. It is never uploaded anywhere, because there is nowhere to upload it to.
The dictionary (39,486 entries), all vocabulary, grammar, stories and example sentences are bundled inside the app when you install it. Lernen works with the network switched off, permanently, by design.
Microphone — only in the Shadowing exercise, where you record yourself to compare your pronunciation with the model. The recording is played back on your device and discarded. It is never uploaded, stored after the exercise, or sent anywhere. If you decline the permission, the rest of the app works normally.
Files — only when you tap "Back up now" or "Restore". Lernen writes a backup file to a folder you choose, and reads one back if you ask it to. It cannot see any other file on your device.
A backup is a plain .json file containing your progress. It is yours. Lernen also opts out of Android's automatic device backup, so your progress is not included in the copy Android keeps in your Google account. "Nothing leaves your phone" is meant literally — which is why the backup file exists. Please use it: it is the only copy of your progress there is.
The optional one-time unlock is processed entirely by Google Play or the App Store. Lernen sees whether the purchase exists (a store receipt on your device) and nothing else — no name, no card, no email.
Lernen is a study tool suitable for all ages. It collects nothing from anyone, so it collects nothing from children either.
Dictionary data from WikDict (Wiktionary, CC BY-SA); noun gender data from the german_nouns Wiktionary extraction (CC BY-SA); word frequency from FrequencyWords (CC-BY); example sentences from the Tatoeba project (CC-BY 2.0 FR). These are datasets bundled into the app — using them involves no network access and no data about you.
Questions: puttosensei@gmail.com