With those files in place my blog now has two pretty awesome features:

1) Offline support. You can read any previously viewed articles on my blog without a network connection. Also, if you attempt to read a new article while offline I display an offline page rather than failing altogether.

2) App install banners: With an app manifest in place, Chrome for Android and Opera for Android now prompt users to install my blog as an app on their device’s home screen. The screenshot below shows the workflow in Chrome for Android:

Although my blog is relatively simple, you can see the potential that these APIs offer. Imagine if Facebook or Twitter’s mobile web sites saved your feed so you could view it offline like their native apps do. Or if news publications removed their desperate calls for users to install their native apps with these browser-implemented install banners.

If you wanna see a progressive web app in action, check out devdocs.io. I use it everyday on both my phone and laptop without a network connection.