Open mobile web is the ability to access websites in mobile view under only one chrome tab. It is an extension offered by Google that lets you pull up your entire website in one tab. You are able to view it the same way as if you are using a mobile device. All of your important stuff can be stored on a single page. These include: reminders, news, calendar, social media, etc. This way you are able to see everything you need without the frustration.
For example, if you are scrolling on Twitter and need to see your reminders so you know when to take that casserole out of the oven, open mobile web does this for you. The same goes for if you want to see what date it is while reading the news, you can do this in a very convenient fashion. Nowadays, multi-tasking is a must, and we are grateful to have the technology to do it.