If you wish to view the VR videos using either an iPhone or an iPad it will be necessary to download the video on a desktop computer first and copy the video across to your device. This is because mobile iOS devices do not allow you to download a video from within the browser and will automatically try to play it instead.
Another option is to use the excellent free Skybox Player which can stream VR videos from your computer straight to your device without having to copy it to the device!