To be honest, I think I prefer your app to my app :P Just move the about section somewhere else (and link to it from the application bar menu). You should also sync the details animations.
Where do you get your data from? Do you use data scraping?
I just had a look at it, going back from a page to the listings gives a full second of a lag/black screen while the Top article screen is being recreated.
You truncate all the article titles. Don't do that, it means I can't read them.
I tried to create the app as closely as the mail app which does exactly the same with truncating, it is part of the Metro style. If you click on an item you will see the full item title.
I'll look into the animation between the item page and main page.
Where do you get your data from? Do you use data scraping?