SiteVault от volyro

BlockGuard lets you build your own blocklist of distracting or unwanted websites.

Features:
- Block any domain (e.g. twitter.com, reddit.com)
- Works in private/incognito windows
- Custom block page shows which site was blocked
- Add or remove sites instantly from the toolbar popup
- Your blocklist is saved locally and persists across sessions

No accounts, no tracking, no external servers — everything stays on your device.