iPhone Screenshots


Test the RPM and wow/flutter accuracy of your turntable, whether 16, 33 1/3, 45, or 78.

RPM is proud to be recommended by Rega Research Ltd, makers of some of the best turntables in the world.

See the speed variations, wow/flutter, of your turntable in real time graphics like you've never seen before.

See the wow/flutter accuracy as the max % deviation from the average rpm of the turntable, as well as graphically in the chart.

Save all your rpm tests in the history log for reviewing or sharing later.

RPM uses the gyroscope in your iPhone to determine the rotation speed of your turntable, automatically determines which speed setting you're on, and reports how accurate it is.

RPM is the ONLY app which shows your turntable's wow/flutter variations.

Simply place your iPhone on your turntable, close to the centre but doesn't have to be over the centre spindle. As the iPhone rotates the display will remain stationary from your perspective for easy reading.

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. You can even detect the small drag caused by the stylus resting in the grooves of the record.

And now with the release of V2 there is the amazing new innovative feature to visualise wow and flutter variations plotted actually around the vinyl centre to show a heat map of exactly where in the turntable rotation the inaccuracies occur.

There are many ways of testing the average RPM of your turntable, many turntables even have this built in, however there is no other practical way of showing the wow/flutter variation over time than RPM.

For Upgraders the history graph parameters can be customised to:
- Set the moving average sample size.
- Accuracy at which to turn the rpm circle sold green.
- Set a duration after which the display updates will freeze so they can continue to be read after the turntable is stopped.
- detect and graph 16, 45, & 78 records.

The graphs kicks in when the rpm accuracy is better than +/- 5% then autoscales to show maximum detail.

Calibration Mode is here! (Upgraders only)
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.
Extensive testing means we're now confident that using RPM can help you setup your turntable to be within 0.1% of its target RPM, assuming your turntable can be adjusted and is itself stable within that tolerance of course.
Use 33 1/3 rpm for auto-calibration as at 45 and 78 rpm the compass simply won't be able to keep up.

What's New

Version 2.95

Show continuous rpm display even if turntable is very inaccurate.

Ratings and Reviews

4.5 out of 5

67 Ratings

67 Ratings

Good for speed


This works very well for general speed accuracy, but is not so helpful for wow and flutter measurement unless you also place another identical weight phone on the platter to closely counterbalance the phone on which you’re running the app.

Without counterbalancing, the weight of the phone, necessarily placed off centre (even if close to the spindle), actually increases wow/flutter - checked by comparison with a test record and frequency measurement.

Developer Response

Hi, thanks for the great feedback.
I agree that wow/flutter is affected the more the phone is placed off centre so for best measurement you should place the device directly over the centre - I use a thin piece if foam with a hole on the middle to support the phone above the centre.

Consider adding scrolling to Settings page


Settings page does not appear fully on smaller screen iPhone 4S and cannot be scrolled to show the rest of it.

Developer Response

Latest update does now enable scrolling on the Settings page, thanks for the suggestion.



Spot on


Philip Broder
46.5 MB
Requires iOS 9.0 or later. Compatible with iPhone, iPad and iPod touch.
Age Rating
Rated 4+
© 2015 Philip Broder
In-App Purchases
  1. Enable Continuous History Graph £4.99


  • Family Sharing

    Up to six family members will be able to use this app with Family Sharing enabled.

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