Measuring TT Speed

I am using the KAB light and disc for those interested...

Lewm, as far as I can tell the RPM app works great. I have a record weight with a flat top so I just put the phone on top of that. The phone reports in hundredths of a revolution. When I first tried it the phone reported a wow and flutter of 1.78 % which sucks. I got a new belt and wow and flutter dropped to 0.07%....on a 40 year old turntable. 
For speed it is certainly more accurate than a strobe. If I adjust it with the phone to an exact 33.33 RPM the strobe is dead still. It is cheap. I suggest you try it and tell us what you think! 

On the other hand, if you can't adjust your turntables speed it might piss you off.

jsman, if you're using the KAB strobe light (and the batteries are good) you should be seeing a series of numbers that correspond with the speed the platter is spinning. So assuming you've got your turntable set for 33.33 RPM you should see a "33" displayed that is stationary (indicating steady speed) or floats slowly left or right depending on whether your turntable is running fast or slow. Not sure what you mean by " the lines on the strobe bounce back and forth."
Tom

Tom,
Are you saying that the numbers should be stationary? That's what I have been doing wrong, I am looking at the bars. For whatever reason I thought the lines were to be stationary....