Android : Save content already seen

i´m creating an app to android/iphone that is a php view of news that I have inserted into my database. All i want to do is, when user launches the app, display, first, the content already seen and then, update to new data. I have tried to use cache manifest, localstorage but nothing works greatly. With cache the page not update. With localstorage page still loading all, and so, it is delaying. I just want a way to "cache" the content already seen but if there is something new in database shows a new content like facebook app and instagram app

tks to all