See the RPM speed variations, know as wow/flutter, of your turntable in real time graphics like you've never seen before, continuous display makes it easy to make adjustments as necessary if your turntable allows it.
The UNIQUE feature of RPM is that it shows a scrolling graph of the rpm accuracy variation over time, this shows wow/flutter effects, especially those associated with the turntable not being level, belt wear, etc.
There are many ways of testing the average RPM of your turntable, some turntables even have this built in, however there is no other practical way of showing the wow/flutter variation over time than RPM.
The RPM realtime display is reliant on the iPhones gyroscope accuracy, if you suspect yours isn't quite right then you can now use Calibration Mode to auto test and then apply any necessary correction in real time.
This auto calibration uses the compass to count the turntable revolutions, if you have an older iPhone (not iPhone 6S or newer) then this may be unreliable, in this case you can still add your own multiplier if you have done an independent calibration.