Visiting the link below generates and takes you to a personalized inbox to which you can POST content from any source. It includes instructions for “installation” on mobile devices so as to benefit from push notifications (which, from a web app, will be a novelty for some, particularly those on iOS).
Building this out, I was pretty impressed at how close one can get to native app capabilities, even to the point of displaying an “unread notification count” on the app icon.
The app is similar to “throwaway” email services except that you can land items in your inbox using a simple http request. This versatility means that you can plug it into a variety of information sources to serve as a dedicated feed. Create and install as many such “feeds” as you like.