There is little information about the uri scheme for the native wp (8.1) twitter app so I took this from the iPhone documentation: http://wiki.akosma.com/IPhone_URL_Schemes#Twitter
This is my C# code, both do not crash and open the twitter application. Just not with the specified user or with the id of the status.
Am I doing something wrong? Or is this still unsupported by the Twitter app on Windows Phone?
private async void OpenTweet(TwitterStatus s)
{
//Uri ut = new Uri("twitter://status?id=" + s.Id); // did not work
Uri ut = new Uri("twitter://user?screen_name=" + s.Author); // does not work
bool success = await Windows.System.Launcher.LaunchUriAsync(ut);
}