In addition to the download of videos via YouTube or other portals is the easiest way to get 3D videos to create them by yourself: 2D video shot with the iPhone/ iPad, with a suitable program, eg. iMovie cut it and then simply convert to 3D with 3D VideoCam.
The base version of the converter is free, the memory function is a single fee € 0,89. The converter has NO time limit.
Here’s the 90-second tutorial.