Benkyou 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. Benkyou keeps your progress — the words and kanji 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 (34,709 entries), all vocabulary, kanji, grammar and example sentences are bundled inside the app when you install it. Benkyou 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. Benkyou asks for the microphone the first time you open that exercise; if you decline, the rest of the app works normally.
Files — only when you tap “Back up now” or “Restore”. Benkyou 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, and it never opens a file you did not select.
A backup is a plain .json file containing your progress. It is yours: Benkyou writes it where you
tell it to and does nothing else with it. If you choose to put it in a cloud folder or email it to yourself,
that copy is then governed by that service's privacy policy, not this one.
Benkyou 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 exactly why the backup file above exists. Please use it: it is the only copy of your progress there is, and a lost or reset phone without one cannot be recovered.
Benkyou is a study tool suitable for all ages. It collects nothing from anyone, so it collects nothing from children either.
Benkyou includes dictionary, kanji and example-sentence data from the Electronic Dictionary Research and Development Group (JMdict, KANJIDIC and the Tanaka Corpus), stroke data from KanjiVG, and pitch-accent data by Uros O. from the Kanjium project, used under the Creative Commons Attribution-ShareAlike licence. This data ships inside the app; none of these projects receive any information about you, because the app never contacts them.
Speech playback uses your device's built-in text-to-speech. Depending on your device's own settings, that may be processed by your operating system's speech service — a component of your phone, not of Benkyou. Benkyou passes it a Japanese word to pronounce and nothing else.
If a future version of Benkyou ever collects anything, this policy will say so before that version ships, and the app will ask you first.
Questions about this policy: puttosensei@gmail.com