If I had a phone I'd get the app and try it on the TD-125. It has had the control board relatively freshly rebuilt and a brand new belt, runs dead centre and incredibly steady on the strobe now, whereas before the rebuild and new belt it would shift a bit for awhile after start-up. Now it spins up more quickly and settles completely in a few seconds. What that means in terms of what the app measures I would be curious to know, but wow and flutter certainly aren't audible which I suppose is the main point in the end, right?