The Wikipedia app has existed for a long time, but it hasn't seen a UI update in quite a while. That changes today with the new version. It has some material design elements and cool new usability features.
Here's the full changelog provided by Wikimedia.
A prominent, contextually-relevant image at the top of each article (with parallax-scrolling) to engage readers in the topic
“Read More” feature at the end of each article that includes links to up to three related pages to encourage readers to explore further
Improved search functionality, including more defined and higher contrast search bar and a list of recently searched topics
Image viewer that allows users to view a larger version of any image via a pop-up panel (image appears unobscured if tapped on) and swipe left or right to view the previous or next image
The way the new app handles images seems much improved. The header image is pulled from somewhere in the article and has parallax scrolling, sort of like the new Play Store client. The image viewer is nicer as well. You can easily get a closer look at an image without losing your place in an article.
There are material influences and animations throughout the app, though the status bar remains a muted gray at all times. For those of you who miss the hamburger animation, you'll be happy to know Wikimedia has your back. It's included here in place of the full-height nav drawer. There are a few pictures of the sold interface below for comparison.