这是来自Chrome商店的 focus 浏览器插件，您可以在当前页面下载它的最新版本安装文件，并安装在Chrome、Edge等浏览器上。
(2) 从设置->更多工具->扩展程序 打开扩展程序页面，或者地址栏输入 Chrome://extensions/ 按下回车打开扩展程序页面
The Internet, a dangerously double-edged sword: half is begging for you to do great things with it, while the other just wants to steal your attention. Spend more time with the first half.
"focus" is the cleanest, most intuitive time-management extension on Chrome that doesn't try to be anything more than it should. Let it know with one keyboard shortcut that you need to get things done, and it will steer you away from a customizable set of websites that you know you can't be trusted with. Tailor which sites you'd like blocked, which it should warn you about, and which it should limit your time on, and then make the internet work for you, free of distractions.
On installation, the extension is granted permission to "Read your browsing history." In practice, the extension is only aware of the page you're currently on. It can't look into the past, it has no memory, and it never trasmits data from your computer.