Show me how to get current URL title and display it in Navbar and also back buttons

I have a app with a navbar and a webview. I need someone to show me how to get the current URL's page title and display it in the navbar. And also I need them to show me how to place a back button in the navbar when goback is available, if goback isn't available in webview then back button must be hidden. You will show me how to do this over freelancer chat or skype.