hello everyone
i am trying to make a browser app
i want a show notification in my browser app
for example
if a user login to facebook account if user allow notification
user show notification of facebook
example - your friend say hi message
you got reply from pooja
etc like a chrome browser
can anyone help me 
It is possible if you can somehow know that the website uses which JavaScript Interface (Usually it is Android)
but how any youtube tutorial ???
Let’s assume a website uses Android tag as JavaScript Interface.
So to communicate with android it will invoke an appropriate method of interface.
Like, Android.ShowToast('Hello! Pooja here.')
Now internally it will call an event of extension where you can choose what you want to do next.
Logically it is possible.
You want to do it the same way as Chrome does?
I don’t think it is impossible, but it is not easy. You won’t find a tutorial to do it or solve it by yourself just with a few blocks.
You must use javascript to do it. It seems you don’t have any idea what is it, so you would have to hire someone.
To get an idea on how it works, see this:
This is and old topic and it is how the websites could make it work. You as a browser developer would have to make your browser work with the websites’s code.