I would think that any turntable that allows for adjustment of the speed of the motor would have this already (based on my limited experience with turntables fr

I would think that any turntable that allows for adjustment of the speed of the motor would have this already (based on my limited experience with turntables from decades ago). So, nice little app, but if it shows you the error of a non-adjustable turntable, it won't have a lot of practical applications.