You use a real computer to download the torrent. Then you use a real computer to transcode the movie for your iDumb device. Then you use real computer with iTunes to upload the transcoded movie to your iDumb device (you can skip this step and stream the movie to the iDumb device from your real computer which surprisingly is not called iAirPlay).
Either that or you purchase the movie in iTunes on your iDumb device and watch it there.
How does one watch the movies? (which app?)
(Genuine questions, I'm curious and don't have one)