This might not be a great information and many people might know it for sure, but few days before I was trying to consume the JSON endpoint and I struggled quite sometime to figure out why the “DataContractJsonSerializer” class is not available in windows phone sdk.

Turns out that you need to add the following two references to make it work:

Add the “System.Runtime.Serialization” and “System.Servicemodel.Web” and now you are ready to rock !