Kakehashi is an unofficial mobile companion app for WaniKani, the kanji learning platform. It provides a native iOS and Android experience for reviews, lessons, progress tracking, study tools, listening practice, song and lyrics helpers, OCR/text utilities, and home screen widgets.

Kakehashi is free and community-built. It requires a WaniKani account and is not affiliated with WaniKani or Tofugu LLC.

When cached assignments are available, review sessions open without waiting for a network check. Completed reviews are saved on the device before the next question appears, and queued results sync with WaniKani when a connection is available. Background refresh keeps the selected review batch stable, replacing only unstarted reviews that are no longer due. Requests that reach an unresponsive connection time out instead of holding the app indefinitely.

On iOS, widget refresh uses Expo's processing task. Keep processing in UIBackgroundModes, and keep com.expo.modules.backgroundtask.processing in BGTaskSchedulerPermittedIdentifiers in both app.json and the checked-in native Info.plist when regenerating the iOS project.

Tap the bookmark on a news card or in the article reader, then find it in Saved articles below Other News, or turn on Saved only in the top filter menu. Easy and Standard stories keep their available article text separately from the rotating news cache. Bookmarks stay on the current device or browser and do not sync between the mobile and web apps. Images and audio still need a connection unless already cached; clearing app or browser data removes saved articles.

If this is your first time working with React Native or Expo, start with Expo's Set up your environment guide. Kakehashi uses native iOS and Android projects, so make sure your simulator or emulator, Xcode/Android Studio, and local tooling are ready before continuing.

Install dependencies:

npm install

Install iOS pods:

cd ios
pod install
cd ..

Run the app on a simulator or emulator:

npm run ios
npm run android

Run on a connected device:

npx expo run:ios --device
npx expo run:android --device

Run common checks:

npm run lint
npm test

Enable Settings → Anki Advanced Settings → Show Kanji Composition to see a vocabulary word's component kanji and their primary meanings alongside its revealed answer in compact cards. Tap a card to open that kanji's details; returning keeps the review answer revealed. On Android, the settings entry is Anki Settings & Export. The option is off by default and works with grouped, meaning, and reading Anki cards. Components appear in word order, using the saved subject catalog for offline review; unavailable components are omitted.

When creating or editing a mobile Subject List, open Browse → Filters → Word Frequency and enter a maximum rank. The list editor uses the same frequency filter as Custom Review, including kana vocabulary. Select Filtered adds all confirmed matches, including those beyond the displayed results. Cached ranks work offline; remaining words can be checked with Jiten and retried if interrupted.

In Custom Review → Filters → Date, choose Lesson completed or Unlocked, then pick a Start and End date. Both options default to the last 7 days. Dates include both selected days in your local time. Select individual subjects or Select Filtered, then use the study button to review them or Add to Lists to save them to Subject Lists. Recent Lessons keeps its existing shortcut behavior.

Use Settings → Review Settings → Review Character Size on mobile, or Settings → Reviews → Review character size on the web, to shrink review prompts down to 30% in 10% steps. The default is 100%; answer fields and other app text keep their own sizes. On the web, you can also change Question text size from the review session's settings button, including on a phone with the keyboard open.

Turn Multiple choice on or off in Settings. Anki questions keep their selected answer mode.

Choose I don't know to reveal the answer and count a mistake. Correct multiple-choice answers follow Stop on correct: with it off, reviews advance automatically; with it on, use Mark Wrong on mobile or Mark Incorrect on the web to correct an accidentally correct selection before continuing.

In the native app, including on a Mac with a keyboard, press D to open subject details from an Anki review, then press D again to return to the revealed review. If you customize the details shortcut, that key also returns to the review. The shortcut pauses while editing a note or using another dialog.

On the web, press D after revealing an answer to open or close subject details, including while a details button, tab, or link has keyboard focus. Closing details returns focus to the review so you can continue grading from the keyboard. This also works with a custom details key set in Custom study keys. Typing in notes and other editable fields keeps its normal behavior.

Use Settings → Appearance → Advanced settings → Learning Pages to add filtered versions of Home, such as one page for radicals and kanji and another for vocabulary. Pages filter by item type, level range, JLPT level, SRS stage and critical items. A switcher at the top of Home moves between All and your pages; each page's counts, forecast, lessons and reviews include only matching items. Without any pages, Home is unchanged.

The mobile app includes a personal Spotify setup guide in Settings → Music Playback → Spotify connection. See the Spotify setup guide for Premium requirements, developer app settings, and the Client ID setup. Song search uses the app’s catalog credentials independently of account linking. Music discovery works over Wi-Fi or mobile data. Empty categories show that no songs were found; failed requests offer Try again for that category.

Contributions are welcome. Please read CONTRIBUTING.md before opening an issue or pull request.