The features include the ability to register an Instagram account. After you take a picture, there are a number of filters that you can use, just like the real site, and you can view images uploaded by friends. You can also share pictures with Instagram using the app. Checking the name of a friend or a particular hashtag, you can search for a specific profile page and view the pictures on those pages.
According to the developer, in progress is a way to "like" photos and comment on them, and a way to view Instagram videos. Another feature being worked on is the ability to share pictures with Facebook and Twitter users. You can check out WLC Gram, currently listed at the Windows Phone Store.
source: WLCGram via WMPoweruser