The stand out feature of the app is the strong design, which does an excellent job of following most of the key principles of Windows Phone's design guidelines, without slavishly copying the design patterns found in the built-in standard apps. It also manages to bring in Reddit's feature set and community ethos without diluting the benefits of being a native app.
The end result is a user experience that truly does measures up to the app's promise of being the "future of Reddit on the Windows Phone platform".
What's also impressive is the degree of platform integration with Windows Phone. There's the expected support for social sharing and Live Tiles (e.g. pin sub-reddits), but also good support for lockscreen integration (backgrounds drawn from images post to a sub-reddit) and notifications (toast and lockscreen).
Also notable is the good support for both standard Reddit features (e.g. complete markdown support) and popular third party services used on Reddit (e.g. Imgur integration with native Album browsing), which creates a more immersive experience and means you're less likely to need to drop into the browser to view content.
Overall app performance is also very good, with little in the way of lag, providing you have a reasonable fast data connection available.
Windows Phone, for some reason, is unusually well served by third part Reddit apps. If you find that Readit is not to your liking check out Baconit or Baconography, both of which, like Readit, combine a well thought out feature sets with polished design.
Windows Phone Store description:
The future of Reddit on the Windows Phone Platform!
Welcome to Readit! A beautiful, well-crafted Reddit app for the Windows Phone Platform. From features like live tiles, a stunning interface, and complete markdown support, you are missing out if you aren't using Readit for your Reddit browsing habits on Windows Phone.
Readit can be downloaded from the Windows Phone Store. A free trial is available, with the full app costing £1.49 / $1.99 / €1.49.