NOTE: this project is not maintained. Check out my newer project DarkHelpers for an updated async collection
An enhanced cross-platform ObservableCollection that let's you use it asynchronously with ease by initializing it with a dispatcher, that all the additions and other actions go through. It also has the AddRange method.
Install NuGet package. PM> Install-Package Divis.AsyncObservableCollection
For information on how to use it please check out the Wiki.