Support
For help, email support@zentsu.app. Include your iPhone model, iOS version, app version and the steps that led to the issue. For a wrong reading, meaning or picture, include the Japanese word.
Words are silent or use the wrong voice
The app uses a Japanese text-to-speech voice installed on your iPhone. In the app's Settings, choose a voice and tap it to hear a sample. Check your volume and whether sound is going to connected headphones or another audio device.
If a Japanese voice is missing, use the voice download guide in the app. On iOS 26, the system path is Settings → Accessibility → Read & Speak → Voices → Japanese. On iOS 18, choose Spoken Content instead of Read & Speak. Download a voice, wait for it to finish, then return to the app.
You can use an installed basic voice or download an enhanced voice from Apple. Downloads need an internet connection. After installation, speech runs on your iPhone.
The meaning appears after a pause
For studied words, the app leaves time to recall the meaning before showing the answer. Tap the card to reveal more. You can turn off Pause before answers in Settings. New words show their meaning, and their picture when they have one, so you can learn the connection.
Restoring JP 2K Full
The first 500 words include every study feature. JP 2K Full is a one-time purchase that adds the other 1,500 words. To restore it after reinstalling or on another iPhone, open the app's Settings and tap Restore purchases while signed in to the Apple Account used for the purchase.
Restoring a purchase restores access to the words, not study progress from another device. If restoration does not complete, email us with the order ID from your Apple receipt. Apple processes the payment; please do not send payment-card details.
Changing a reminder
Open Settings in the app to enable or disable the daily reminder and choose its time. If notification permission is off, allow notifications for Learn Japanese in your iPhone's Settings. Completing a daily round can suppress that day's reminder.
Progress and resets
Your study progress, heard words and settings stay on your iPhone. They do not sync between devices. Deleting the app removes its local data; copies in an iPhone backup follow your backup settings.
Reset heard progress clears the record of words you have listened to. Reset study progress clears your learned and studying words and their review schedule. These are separate actions in Settings, and each asks for confirmation.
Offline study and corrections
The app includes its vocabulary and pictures. Once a Japanese voice is installed, study works offline. Word and picture corrections arrive through app updates.
Sources and privacy
Read the word sources and data license or the app privacy policy. The app is also referred to as JP 2K, and its optional purchase is named JP 2K Full.