Android: When you click on a link in some apps, you might find you open a small, stripped-down web browser without leaving the app. While this is nice, it lacks a lot of useful features of Chrome. Chromer fixes this. Chromer uses a feature called Custom Tabs to create a better, more seamless browsing experience. This improves on the old-style System WebView by making use of the full Chrome engine in a browser tab without actually leaving the app.
If you don't know what that means, don't worry. The important takeaway is that with Chromer you can use all the features you like from Chrome without having to leave the app you're using. You can do things such as access your stored passwords and use Chrome's data-saving mode. Just make sure you're running Chrome v45 or higher on your device.