In my app. I am using all web views and that ar opened from app.js in win1 window but I want to add one tabbed bar as a "back" button how can I add it and how it can work as back button.
The back button is automatically added when you create a child window, it sounds like in your case you'd have to add that manually as well as manually keep track of which window is visible right now and which one to go to when a back button is tapped.
What I would try is putting a variable in app.js to keep track of which window is being shown right now, and have an array of the URL's that app uses so you'd be able to figure out which one to open based on where the user is right now. Then manually create a button object with the title "back", and and add an event listener to that button to call a function to sort out were to go back to, then open that URL.
Hope that helps.