Microsoft started talking about their metro IE10 browser in Windows 8 which is aimed for touch screen devices, here IE blog explains developers how to connect their websites to Windows 8 apps. Metro browser lets you navigate from a website to its associated metro app installed in your PC, all you need to do is click on “site icon” at the bottom to “switch to that app”.
Easily know the existence of associated metro apps for websites in Metro IE
You can know whether associated metro app exists for the website you visit in metro browser by looking at the site icon, when IE discovers metro app for the site you’re on, site icon will turn into a button which on clicking opens app description in Windows store. Desktop IE10 doesn’t offer this linkage between website and its associated metro style app.
Don’t forget in Windows 8 Developer preview by default IE10 set as default browser, so whenever you receive a link via email on clicking opens in metro Internet Explorer.
So metro IE makes it easy to discover metro apps for associated web sites, you can switch to particular app if installed in your PC or tap on site icon to get it from the windows store.