PianoMeter – Piano Tuner3.2.1 - App Store

PianoMeter is a piano tuning app that will transform your iPhone or iPad into a professional quality electronic tuning aid.

NOTE
The "free" version of this app is primarily for evaluation, and it only allows you to tune notes on the piano between C3 and C5. To tune the entire piano you will need to buy an upgrade through an in-app purchase.

What makes PianoMeter unique:
Unlike regular chromatic tuning apps that simply tune to a pre-calculated equal temperament, PianoMeter actively measures the tonal characteristics of each note and automatically calculates the ideal “stretch” or offset from equal temperament. In other words, it creates a custom tuning for each piano with the best compromise between intervals like fifths, fourths, octaves, and twelfths, the way aural piano tuners do when fine-tuning.

Functionality and pricing:
There are three levels of functionality: a free (evaluation) version, a paid "plus" version with basic tuning functionality, and a "professional" version with features geared towards professional piano tuners. The extra functionality is unlocked through one-time in-app purchases.

The Free version includes the following limited functionality:
. Tuning functionality for the mid-range of the piano only
. Automatic note detection
. Ability to measure each note on the piano to see how its current tuning compares to the ideal tuning curve (see if a piano is roughly in tune)
. Swipe in the graphing area to show a live frequency spectrum or the inharmonicity of measured notes.

Upgrading to "Plus" adds the following functionality:
. Tuning functionality for the entire piano
. Tune to frequency standards other than A=440
. Tune to historical or custom temperaments
. Calibrate device to an external frequency source

Upgrading to Professional unlocks all features of the "Plus" version, plus the following:
. Save and load tuning files, so a piano doesn't need to be re-measured each time it is tuned
. Pitch raise mode that calculates overpull for an initial first pass "rough" tuning (for pianos that are extremely flat)
. Custom tuning styles: create a custom tuning curve by adjusting interval weighting and stretch
. Multi-partial tone generator that plays the target frequencies
. New colorful "Tonal Energy" display that shows a brief history of the pitch
. Access to all future features and enhancements

Upgrade costs:
Free to Plus (approximately US$30)
Free to Pro (approximately US$350)
Note about permissions
This app requires permission to access the microphone on your device and permission to read and write files.

Version History • Fixed occasional freezing after a phone call or notification
• Deleted tunings can now be recovered when iCloud sync is on
• Wider range for extra treble and bass stretch, and the slider now moves in whole cents
• Minor bug fixes 3.2.1 Aug 18 • Cloud sync (Pro): keep tuning files in sync across your Apple devices via iCloud
• Tuning history (Pro): automatic per-piano tuning records, with nearby-piano suggestions when opening files
• Audio input channel selection with external-mic indicator
• Peak View now included with Plus
• Better battery life while tuning, plus many fixes 3.2.0 Jul 22 Bug fixes 3.1.1 Apr 7 - Grab and spin dial to quickly change the pitch offset. (Double tap or long press on the indicator at the top of the outer ring to activate.)
- Add high resolution option for tonal energy display
- Doubled resolution for Peak View graph 3.1.0 Mar 13 For Pro users:
• New Adaptive Bass Stretch auto-adjusts bass interval weights by piano size. To turn off, set Adaptive Bass Stretch to zero in Style.
• Interval weights rescaled (all styles migrated)
• Bulk-apply any style to all tunings (long press)
• New low stretch style (for PTG/RPT exam)
• New tonal energy color palettes
• Inharmonicity weight factor now managed in tuning styles
For all users:
• Improvements to unequal temperament management and inharmonicity detection 3.0.0 12/21/2025 Added options to hide the reminder to measure several notes and the tuning curve legend. Legend now hidden by default.

Bug fixes and updates. 2.1.0 08/27/2025 Add Tonal Energy waterfall display and graph (pro)
Add Welcome tutorial
Add Pure Eleventh interval to weights. (Improves balance for bass intervals)
Overhaul tuning style management
Swipe to change the note by an octave. (Tap for half step)
Add a multi-partial tone generator (pro)
Add audio input preference selector
Add a separate pitch raise overpull limit for bass
Many behind-the-scenes improvements (inharmonicity, note detection)
User-adjustable strobe ring contrast
Add coarser dial 2.0.0 05/29/2025 • Added the ability to adjust the contrast of the spinning strobe rings.
• Swipe to advance the current note by an octave, and tap to change by a semitone (instead of tapping for both).
• Added the ability to search tuning files by serial number.
• Added separate pitch raise overshoot limits for plain wire versus bass strings.
• Added a reminder to measure several notes before beginning to tune.
• Added the Preleur temperament as a built-in option.
• Fixed bugs with the placement of blue dots on the Styles page and with non-equal temperaments not loading from saved tuning files. 1.5.0 09/18/2024 • Added option to select whether an external mic or built-in mic is preferred for audio input
• Improved layout of the Tuning Style (interval weights) graph
• Added a 70Hz highpass filter on incoming audio to reduce the effects of low-frequency noise
• Several small fixes & updates 1.4.0 04/10/2024 App will now accept input from external microphones.
If the pitch offset of a loaded tuning doesn't match the global default for pitch (eg. A=440) it will appear red in the infobox. 1.3.7 02/02/2024 Bug fixes:
Fixed missing comma for decimals on numeric keyboard for pitch settings
Made "Restore purchases" button more visible and added an automatic license refresh 1.3.6 03/02/2023 Minor updates and bug fixes 1.3.5 11/11/2022 Fixed audio input bug affecting certain devices running iOS 15
Lowered threshold for automatic note switching (more likely to change notes) 1.3.4 11/16/2021 Fix bug affecting iOS 12 1.3.3 10/10/2021 Add compatibility for iOS 15
Raise minimum required iOS version from 11 to 12 1.3.2 10/05/2021 Added a setting for a pitch raise overshoot factor
Fixed a bug with dots on the Tuning Style graph
Increased highest possible value of "lowest unwound string" from A3 to D4 1.3.1 07/19/2021 Added new screen with various options on startup
Tweaked flow of various processes (new tuning file, pitch raise)
Updated non-English localization 1.3.0 04/08/2021 Fix bug affecting the management of relative partial strengths (may slightly improve calculated tunings, including for previously stored files)
Improve naming convention for exported tuning files 1.2.1 02/13/2021 Added subscription option for the Pro version
Added dark theme
Added ability to reset inharmonicity measurements for individual notes and pitch measurements for all notes (long press in graphing area)
Added workaround for the inability to enter a negative sign in number boxes by using a ± button above the keyboard 1.2.0 02/01/2021 Fixed decimal values for custom temperaments, added option to save default sort order of tuning files
Fixed crashes caused by Dropbox trying to backup without internet 1.1.2 11/25/2020 Bug fixes - negative sign on keyboard for cents entry, audio resumes after phone calls 1.1.1 10/04/2020 Add localization to support multiple languages and explanatory "toast" notifications to confirm certain actions (note switching, etc.) 1.1.0 08/15/2020 1.0.0 08/05/2020