I have MX Player from Google Play on my HD and HD+ and it plays everything just fine. I'm pretty sure I've played .vob files with it, although I'm not 100% certain I have.
They have a free ad supported version so you can try it and see.
Check out the program, Handbrake. It will allow you to convert the video to a considerably smaller and more appropriate .mp4 file. Be aware that the HD/HD+'s native video player doesn't handle anamorphic files properly. If you need this functionality to work correctly, try a 3rd party viewer. The MX Player mentioned above is a great app.
Thank you for using DVD Catalyst.
Anyway, if the DVD contains just a vob file, it is not a DVD in the actual DVD standard, and DVD Catalyst will not recognize it as such. Just drag the vob file over (from the DVD or from your computer) on top of DVD Catalyst, and it should scan/convert it in video file mode.