For a long time now manufacturers have been un-bundling specific apps from their operating systems. This means apps that come built into your phone like Email, browser and other manufacturer specific apps very likely available in the Google Play Store, albeit only for your specific device. This allows manufacturers to push out feature and security updates as needed rather than have to perform a complete operating system update just to get these sorts of system apps to their latest versions. With the introduction of Android 5.0 Lollipop Google brought about some changes to the OS that include breaking off more apps built into the OS just like many manufacturers have, one of which included Google's WebView app.
It took a little while before we actually saw this idea come to fruition for WebView but it finally happened in the beta channel of the Google Play Store just last month. Since beta tests are only open to those invited to participate in them it's likely that only developers have been able to see this listing in their Play Store search results. Today Google is changing that, however, and is making the WebView app available for all phones running Android 5.0 and 5.1 Lollipop. If you're not exactly sure what WebView is or why you even need it, don't worry, it's already been built into Android for many years now and it's something you likely use all the time without realizing it.
WebView is a way for developers to use Google's webpage rendering engine to display websites from within their apps without having to redirect you to Chrome or whatever other browser you use. This keeps people inside the app in question and from getting too distracted and going to other apps, which is something developers usually want to do. Having this specific piece of Android decoupled from OS updates keeps things more secure and of course allows Google to add additional features when needed. As is the nature with anything digital there will always be security vulnerabilities and ways to crack the system, so it's important for a company like Google to be able to update this important part of Android without waiting for carrier approval or getting it caught up with other less important sections of the OS. Check the Play Store listing below to make sure you're up to date if you're running Android Lollipop on your phone!