Effective: October 10, 2026 · 한국어
Sprout Island Sports Day ("the app", known in Korea as 새싹섬 운동회) is a game for players of all ages, including elementary and middle school children. The app is published by SYNOF Studio (Republic of Korea). There is no sign-up, and the app uses only the minimum information needed to run the game. In particular, it is designed not to collect personal information from children under 14.
| Item | Details | Where it is stored |
|---|---|---|
| Anonymous user ID | A random identifier created automatically without sign-up. Used for friend rankings (Group League) and the World TOP 10. It is not linked to any name or phone number. | Server (Google Firebase) |
| Nickname | Under 14: cannot type a nickname; chooses one made by the app (e.g. "Brave Squirrel"). 14 and over: may type a nickname. Profanity, phone numbers, addresses, social media IDs, etc. are filtered out. | Server. Visible to friends in the same group and, if you place in a World TOP 10 (1st–10th per game), to everyone using the app. Children only ever see app-made names; typed names are shown to them as a character name (e.g. Sprouty). You can opt out under Settings › World TOP 10. |
| Group name and invite code | The name and random code chosen when creating a friend group | Server |
| Game records | Scores and times per game (the World TOP 10 keeps this week's and all-time bests and when they were uploaded), kart driving records for ghost karts (in-game coordinates, not real-world location) | Server and device |
| Birth year | The birth year chosen at first launch. Used only to choose age-appropriate screens and ads. | Device only — never sent to the server |
| Purchase records | In-app purchases are processed by Google Play or the App Store. The app stores only which product was bought and the purchase confirmation value on the device. We never receive card numbers or other payment details. | Store and device |
| Purchase check value (hash) | When the Full Version is bought, the store's purchase confirmation value is turned into an irreversible SHA-256 hash and registered on the server with the product name and platform. It is used only to turn the Full Version off when the store reports that the purchase was refunded or cancelled. It is not linked to the anonymous user ID. | Server (Seoul) |
| Live match data | Only when playing "Play Online": room code, displayed name (nickname or character), chosen character, kart and kart looks (paint and boost trail), in-game positions, scores and results during the match, and connection signals. Not real-world location. | Server (Google Firebase Realtime Database, Singapore). Deleted when the room ends. |
| Report records | When you report someone's name: the anonymous IDs of the reporter and the reported player, the reported name, the reason and the time | Server. Kept so the operator can review reports and prevent repeat problems. |
| Usage totals (daily counts) | Only daily total numbers such as "how many devices opened the app for the first time today, how many games were played, how far players got in Stage Challenge, how often the Full Version screen was shown". The totals contain no anonymous user ID, nickname or device information, so nobody can tell whose activity they are. To stop the numbers from being inflated, the server keeps a counter of how many events each user sent that day (stored under an irreversible SHA-256 hash of the anonymous user ID and the date) and deletes it automatically after eight days. | Server (Seoul). Used only to improve the app. |
| Change Phones bundle | Only when you make a code in Settings › Change Phones: this phone's game record files (coins, medals, records, decorations, settings, nickname, groups, kart driving records) and the anonymous user ID. Birth year and purchase records are not sent (the new phone asks again, and purchases come back with the store's "Restore Purchases"; to avoid granting purchased coins twice, purchase confirmation values move only as irreversible SHA-256 hashes). The bundle is deleted as soon as the new phone finishes, or within an hour after 24 hours if it is never used. A bundle whose transfer was started but never finished is deleted after 7 days. After a move, only a "moved" marker (SHA-256 hash of the code, anonymous user ID and time — no records) is kept for one year so the old phone can find out. | Server (Seoul) |
| Advertising information | Google AdMob may process device information to show ads (see section 5). |
We do not collect: real names, phone numbers, email addresses, home addresses, location (GPS), contacts, photos, camera or microphone, or school names. The app does not request these permissions. There is no chat in the app.
Only to provide friend rankings and ghost karts, save game records, set age-appropriate ads, deliver in-app purchases and check refunds, move records to a new phone (Change Phones), and improve the app (daily totals). We never use it for other purposes and never sell it.
Server data is kept in Google Firebase until the user deletes it. Data on the device is removed when the app is uninstalled or deleted as described below. Report records are kept for up to one year for review, even after "Delete My Data", and then deleted.
Friend rankings, the World TOP 10, ghost karts, groups, report records, purchase check values and usage totals are stored in Seoul (Republic of Korea). Live match data for "Play Online" is sent to and stored on Google Firebase Realtime Database servers in Singapore (recipient: Google LLC; purpose: live matches; retention: until the room ends). Nothing is sent there unless you play online.
Tap Settings › Delete My Data in the app to immediately delete your nickname, records (including the World TOP 10), ghost karts, group memberships, live match data and anonymous account on the server, and all data on the device. Groups you created remain for your friends, but your creator information is removed and the group is renamed "Sprout Island Friends". One-time products (the Full Version and the Starter Pack kart) stay with your store account and can be restored with "Restore Purchases", but coins already received (including Starter Pack coins) and any remaining Sprout Pass time are not restored. Daily totals and purchase check values cannot be linked to anyone, so there is nothing personal to delete there, and the daily counters (hashed) are deleted automatically after eight days.
We do not share personal information with anyone else.
We sell only two products: the Full Version (a one-time purchase you keep: Stage Challenge 11–30, no ads between games, unlimited hearts, 2× coins, 3 exclusive karts and 5 exclusive kart looks, and new games and courses added later) and the Sprout Starter Pack (one time only: the Sprout SUV kart and 3,000 coins). There are no subscriptions and no automatic charges. Prices are as shown in the store. We do not sell random rewards (loot boxes). Payments are processed by the store, and a grown-up check is shown before paying. Refunds follow each store's refund policy; if a purchase is refunded, the Full Version is turned off.
Email: synofstudio@gmail.com (also available from Settings › Parents › Contact Us in the app, and the developer contact on the Google Play and App Store pages).
If this policy changes, we will post the update on this page with a new effective date. If the English and Korean versions differ, the Korean version prevails.