Notyfy aggregates your notifications across various platforms and displays them in one place. Clicking on the notification will guide you directly to the notification's platform and its content.
By the way, you can read more about the Notyfy extension and Simon, the developer behind it in his interview. Enjoy!
The extension doesn't require any login details. Sensitive data like passwords are never read or stored. Notyfy sees which of the available platforms you're logged in and gets the notifications from them.
Notyfy uses optimized checks to save bandwidth; for instance that means for Facebook it only takes 0,002% of the size of the manual Facebook site check. For this example Notyfy uses between 0.7kb to 58kb while regular browsers up to 25mb.