Terms of Service

Effective 2026-10-17

These terms cover the Hidden Vowels (오늘의 초성) web app (chosung.dosaem.com) and the iOS and Android apps. Using the service means you accept them.

1. What the service does

One masked word per day. The puzzle changes at midnight Korea Standard Time (KST), with one puzzle per puzzle language (Korean and English). There is no sign-up: the guest token stored on your device owns your records. These terms are available at any time from the service and on this page.

2. Linked accounts and backup codes

Linking a Google or Apple account lets you continue the same records on another device. Without an account you can still move your records with the backup code shown under "back up my records". That code is the key to your records, so do not share it. If you lose the code and never linked an account, there is no way to recover the records.

3. Ad-free subscription

In the apps, a monthly subscription (product ID adfree_monthly) removes banner and interstitial ads and unlocks hint previews without watching an ad.

Product name

Ad-free subscription — an auto-renewing in-app subscription (not sold on the web).

Price

Whatever App Store or Google Play shows for your region (₩1,500 per month in Korea). The amount shown on the store's purchase sheet is what applies.

Length and billing period

One month. The benefit starts immediately and billing repeats on the same cycle.

Auto-renewal

This subscription automatically renews unless you cancel at least 24 hours before the current period ends, and your store account is charged.

Cancelling

You cancel in the store — on iOS, Settings > Apple Account > Subscriptions; on Android, Google Play > Subscriptions. Benefits stay active until the end of the current period. Deleting your account in the app does not cancel the subscription.

Restoring

After changing devices or reinstalling, use "Restore purchases" on the subscription screen to reattach a subscription bought with the same store account.

4. Withdrawal and refunds

Billing and refunds for the subscription are handled by App Store (Apple) or Google Play (Google). The operator cannot see your payment method or transaction history and cannot process a refund for you — please ask the store directly.

• App Store: report the problem from your purchase history at reportaproblem.apple.com.
• Google Play: use the refund request form at support.google.com/googleplay.

Under Article 17 of the Korean Act on Consumer Protection in Electronic Commerce you may withdraw your purchase within 7 days of payment. However, Art. 17(2)5 allows that right to be restricted for the part of digital content already supplied — the ad-free benefit applies from the moment of purchase. You can still withdraw for a part not yet supplied (a future billing period, for example), and an accepted withdrawal is refunded to your payment method under the store's policy.

If the subscription did not do what it promised (you paid and ads kept showing, for example), write to the email in section 11. We will find and fix the cause and help you document the transaction for the store's refund request.

5. End User License Agreement (EULA)

Use of the app itself is governed by Apple's standard Licensed Application End User License Agreement: Apple standard EULA.

We decided to use the standard EULA as is (spec open question 9, 2026-10-14): this app has no licence terms that differ from the standard agreement, and using the standard one means no separate terms have to be entered in App Store Connect. If a custom EULA is ever needed, the link in this section will point to it.

6. Rules of use

• Do not submit answers or manipulate the leaderboard with automated tools or scripts.
• Do not disrupt the service with excessive API calls (rate limits apply).
• Do not try to obtain anyone else's guest token or backup code.
• Do not scrape the word and hint data in bulk to redistribute it elsewhere.

Where we confirm a violation, we may remove the affected records from the leaderboard or restrict access.

7. Changes and interruptions

This service is run by one person, so maintenance, incidents, or shutdown may interrupt it temporarily or permanently. During maintenance the app and web show a maintenance screen. If the service is to shut down, we will announce it in the app and on the web beforehand, and the announcement will say what happens to any remaining subscription period.

8. Limits of liability

The service is provided "as is". For the free features we are not liable for damages from lost records or leaderboard errors. For the paid subscription we are responsible for providing the ad-free benefit during the period you paid for, and not for damages beyond that. Consumer rights guaranteed by applicable law are not limited by this section.

9. Privacy

What we collect, how long we keep it, how to delete it, and where it is transferred are set out in the Privacy Policy, which is also reachable from the app's settings screen and the footer of this page.

10. Changes to these terms

When the terms change we update the effective date on this page and announce significant changes in the app and on the web. Continuing to use the service after that announcement means you accept the updated terms.

11. Governing law and contact

These terms are governed by the laws of the Republic of Korea. For questions and complaints, write to [email protected]. Korean consumers may also use the counselling and mediation service of the Korea Consumer Agency (1372) under the Framework Act on Consumers.