pulling data from a website in android application
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I want to ask, I have a website(HTML and javascript) that allows user to login, maintain thier account. Now I want to create an android application that allows user to login and then pulls thier account details from the website and display on the android app. I have no idea where to start? After user logged in how to pull that user's account details from website? Any suggestion where to start and what to look for??? 