No, you do not have to use the WD software or app to view the drive or play media. Once you configure the drive it will look like any shared drive would look on your network. You can connect directly to it from your computer file browser and play any video/audio files directly like you would a file stored on your computer.
I use an app on my iPhone/iPad/AppleTV called GoodPlayer and it connects directly to the file share and plays the video. You could use any app that can play a video from a windows file share.
I've actually not even used any of the WD software with it yet, including the app. I do need to try the app though...
This drive is truly a portable NAS (network attached storage) device once it's setup on your network. But it can do a whole lot more for you than just that. I am truly impressed with it. Worth every penny.