I decided to create my own 3D stereo image programmatically.
Hold the phone about 12 inches from your face. Focus your eyes to an imaginary point behind the phone, until the two red squares become three. The 3D effect takes place in the middle square.
Here are my hand-written notes, showing how I computed the x and y screen coordinates for the left and right eyes, for a single point at some absolute x, y, and z position.