← Wordstack

Privacy policy

Effective October 17, 2026

Wordstack is a vocabulary flashcard app made by an individual developer (JEON-SM). It is available as a web app, a Windows app and an Android app. This policy explains what data Wordstack handles and where it goes.

Summary

• Wordstack has no server. The developer never receives your cards or any other data from you.
• Your cards, folders and settings are stored on your device.
• Google sign-in is optional. If you use it, your data goes only between your device and your own Google Drive.
• No ads, no analytics, no tracking.

Data stored on your device

The app stores the folders and cards you create (words, parts of speech, pronunciations, meanings, definitions, examples, notes, formatting, difficulty marks, the "memorized" flag), the dates each card was created and reviewed, and your settings. It is kept in your browser's or the app's local storage on your device. Dictionary API keys you enter in Settings are stored only on that device and are never synced.

Google account (optional)

If you choose Connect Google in Settings, Wordstack asks for:

• Google Drive application data (https://www.googleapis.com/auth/drive.appdata): to create, read, update and delete Wordstack's own files in the hidden application data folder of your Google Drive. These files are a sync file (wordstack-sync.json) containing your folders, cards and review history, and up to 14 daily backups. Wordstack cannot see or access any other files in your Drive.
• Your email address: shown in Settings so you can see which Google account is connected.

Data is sent directly between your device and Google. Access tokens are kept only on your device. Wordstack does not send your Google data to the developer or to anyone else, does not use it for advertising, does not sell it, and does not let people read it. Wordstack's use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements.

Services the app contacts

To fill in cards, the app sends requests directly from your device to these services:

• Merriam-Webster Dictionary API: the word you look up and your own API key; pronunciation audio files are loaded from Merriam-Webster when you play them.
• Wiktionary (Wikimedia Foundation): the word you look up.
• Free Dictionary API: the word you look up, only when no Merriam-Webster key is set.
• Google Identity Services and the Google Drive API: only if you connect Google.

Links to Naver Dictionary and the Cambridge Dictionary open in your browser only when you tap them. Each of these services has its own privacy policy. Reading aloud uses your device's built-in text-to-speech voices.

Keeping and deleting your data

• Cards and folders stay on your device until you delete them in the app or remove the app or its data.
• To stop syncing, choose Disconnect in Settings. You can also remove Wordstack's access at myaccount.google.com/permissions.
• To delete Wordstack's files from your Drive, open Google Drive on the web → Settings → Manage apps → Wordstack → Options → Delete hidden app data.

Children

Wordstack is not directed at children under 13 and does not knowingly collect data from them.

Changes

If this policy changes, the new version will be posted on this page with a new effective date.

Contact

Questions about this policy: contact the developer through GitHub.