Parents pick the apps and sites; kids browse safely with no way out except your PIN. Runs offline. Syncs across your family's devices.
Get Koyster →Kiosk mode with defense-in-depth: no way to exit the app, no address bar, no Ctrl+Alt+Del escape. Your parent PIN is the only key.
Fifty+ hand-picked educational sites organized by subject, auto-recommended for each child's age. Add your own too.
Set a daily cap per app. Give kids reading or practice goals ("20 min on Khan Academy") that auto-complete when done.
Each kid gets their own library, their own settings, and their own custom style. No shared logins, no sibling drama.
Encrypted cloud sync keeps profiles the same on every family device. Works offline too — changes push when you reconnect.
No ads. No tracking. No selling data. Built around children's privacy law (COPPA). Child PINs never leave the device.
Windows, macOS, and Linux. Enter the license key from your purchase email when the app asks.
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30-day money-back guarantee.
Have more than 3 kids? Add extra profiles ($1 each) at checkout, or any time later from Settings.
Koyster is a native desktop app for Windows 10/11 and macOS 11+. A Linux build is also available. iPad and Android versions are on the roadmap.
With Koyster's built-in defenses alone, kids can't close the app, disable full-screen, open dev tools, right-click, or use most keyboard shortcuts. Ctrl+Alt+Del triggers our defensive re-lock (the child is bounced to the parent PIN on return). For airtight lock-down, our setup guide shows you how to enable your OS's kiosk mode (Windows Assigned Access, iPad Guided Access, Chromebook kiosk) in a couple of clicks.
No. Only the parent creates one account. Kids never see a sign-up form.
Buy Koyster above and we'll email your license key. Download and install the app, create your parent account, then enter the key when Koyster asks. Already set up on one computer? Sign in on another with the same account and your license comes with you.
We designed Koyster around the US children's privacy law (COPPA). A parent has to create the account and give consent before any child profile exists. We only store a nickname, age, and app settings, in your private account so they sync across your devices. Nothing is sold or used for ads, and you can export or delete everything anytime. Full details in our Privacy Policy.
If Koyster isn't right for you, email support within 30 days for a full refund.