Question and consultation on login integration with facebook

I am following a pretty good tutorial I understood perfectly. But I have a question and hope you can help me solve it. In our facebook application must be set to use the url validity. I, personally, work locally on my computer. So my site’s URL is something like


Logically this can not submit a valid URL. my question is, is the device that url? With that URL I set my application on facebook?

I also would like to open the Facebook application in the event that is installed on the device.