The browser add-on

Optional, and worth two minutes if you study in a browser.

What it does

Without it, your browser is one item on the list. With it, each tab is judged by itself, so leetcode.com can be the work while youtube.com isn't. It works in Chrome, Brave and Edge.

How to add it

1. Download focusos-browser-addon.zip and unzip it somewhere you'll keep it.
2. Open chrome://extensions (brave://extensions, edge://extensions).
3. Turn on Developer mode, top right.
4. Choose Load unpacked, and pick the folder you unzipped.
5. Click the FocusOS icon and paste the pairing code from FocusOS's first screen.

Your privacy

It sends the list of your open tabs to FocusOS on your own computer (127.0.0.1), only with your pairing code. It can close a tab when you tell FocusOS to. There's no server involved.