He's stated that he doesn't want to have a smartphone and doesn't want to get one just to trigger the camera.
Well, he said iPhone, but he could get either an iPhone or an Android phone, and there are Android phones out there a lot cheaper. Regardless, without one or the other sending him the links for the app isn't helping him, I don't think. Choices are:
Get a different camera that has some directly-connected remote release capability
Get a smartphone
Give up on remote shutter release