The way that the camera app run to photo app is changed.
Windows 8.1 Blue and ealry version)
Windows.System.Launcher.LaunchUriAsync(new Uri("ms-photoviewer:?album=CameraRoll"));
Windows 10 Mobile) There is no infomation about this issue how to run photo app. By accident I found it.
Windows.System.Launcher.LaunchUriAsync(new Uri("ms-photos:"));
But I don’t know that how to display CamearaRoll, tried to do “ms-photos:?album=CameraRoll” and “ms-photos:?album/CameraRoll” and etc…