App that Uses Data from Website

I am looking to create an app that shows data from my website. Can any one give me an idea of how to go about having the app get the data? The app would have different sections to correspond with pages on the site such as Home, Contact, etc. Each section in the app that the user can tap should show the info from the corresponding page on the site. I don't want it to just take the users to the site. I want it to show the info in the format of the app. So when a user selects an article or list of contacts for example, it should show everything within the app and keep the look and feel of the app. So, basically not take you to the actual site like, for example, the Facebook app does. Any direction is greatly appreciated.

Thanks in advance!

 

The articles will actually be coming from a Wordpress site. The app will have different sections for users to go to for different types of articles. I will need to have each button go to a certain part of the site. Also, is it possible to narrow some articles by only looking for certain tags?

 

I'd like to utilize RSS.