Button back to the application after opening browser

I have a webview that loads a particular site in it the user has to do a validation that can only be done by the browser, the user clicks on the link and opens the android browser and does this validation, it is possible to create a button back to the application on the top of the browser because after the validation the user has no way back to the application, on the iphone there is the navigation controller and when the user clicks on a link that opens browser is created a back button on top of the mobile is possible on android?