Minority need - maybe. I could definitely envision several things I would like to try, if I was to gain a bit better external control of my camera.
For instance, I have a gorillopod tripod, which (for instance) enables interesting new angles on things like party shots, but if you position the camera out of normal reach so is the camera screen. I have a remote for shutter release, but I have to basically compose the shot beforehand.
Or - I could use my gorillopod at the bird feeder or near the fox den in our nearby forest, or any sort of wild-life related scene.
Or I could more easily compose shots with myself included.
Sure, it's just a toy gadget, but although I have managed to sell a few bird shots this year, my camera will remain first and foremost my favorite toy. A new fun accessory for my favorite toy - good enough for me!
I know there are some tablet-based solutions, but they seem to require more of a specialist set up (like connecting the camera to a pc?) which are impractical in a more spontaneous party/travel/walk-in-the-park type situation - and they would require me to buy (and bring) a tablet too. My phone is mostly always at hand, and an app would not require additional packing and planning...