How to play mp4 videos on pandigital novel android multimedia ereader white 7"?

I have a white pandigital novel 7 and would like to learn how to play mp4 movies. What app do I need on the tablet in order to play mp4 movies. I have movies downloaded on my computer already with the help of a firefox add on, Video Download Helper ,and I am able to watch them on my computer. I put one on my 8gb sd card to see if I can play it on my novel. All I heard was sound and no video. Can someone please help me figure this out. TIA