> Out of interest how long does the camera-moving step take?
Around 1 second. You only have to move the phone a tiny bit (maybe 3cm)
Half a sec on my N5 (go slower and it actually complains). It's even shorter with good lightning and with a bit of habit it can come out quite naturally. Frame, snap, slide.
I would say that it takes about 1 second on my nexus 4. If you do it too fast the app will complain, but I find that it's actually very fast and easy to do right.
It still seems like a problem to me, if your subject (and potentially background) are moving around a lot. I shoot a lot of macro shots of bugs that are always about to jump off plants that are swaying in the wind... Not to say this tech isn't impressive and useful, but it doesn't solve DoF problems for tiny cameras in every situation.