StillSpaceDownload StillSpace
Free for Windows and macOS.
Windows
1. Run the installer. If Windows SmartScreen appears, choose More info, then Run anyway (the app is new and not yet widely recognised).
2. Open StillSpace. Right-click it and choose Run as administrator the first time, so website blocking can edit the hosts file.
Browser extension
For page-level blocking (like youtube.com/shorts) and the blocked page, add the StillSpace Blocker extension to Chrome, Edge or Brave. The Support page has the steps.