Wikipedia may not be accepted in all schools as a source for research papers but it is dandy a great source for regular information. This is the first app that I have seen that not only has a clean and easy to use UI it also has no bugs that I have noticed. Windows8update.com also made a review of the app and they loved it just like me.
The app starts up very fluidly and has no noticeable bugs in this current iteration. Performance in my perspective is much faster than the browser version in Google Chrome. The information is nicely spread out and takes 2 seconds to start up. It shows four columns featured pictures, featured articles, on this day in History, and recent changes. On my computer the app does not looked either stretched and pixel peepers would be satisfied. Clicking on an article brings up a horizontal row of words and depending on the article it will show on average the usual info box which either tapping or clicking on it will bring up a pop up box that you can close out by tapping the article again. Also below that is a table that when tapped will lead you to other articles that pertain to this article or if it is in a chain of events. Going from left to right will take you to the rest of the article and references. Fluidity and an easy to use interface makes for a great app and no qualms about it.
I found that the Windows 8 Wikipedia app is the best app in general so far I tested other than the TuneIn Radio app.