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FQC

Measure Frequencies & Musical Notes

FQC is a precision audio frequency counter for iPhone.

Measure frequencies from 50 Hz to 20 kHz using your device microphone, identify musical notes in real time, and monitor signal levels with a clear, easy-to-read display.

Designed for musicians, electronics enthusiasts, audio technicians, students, hobbyists, and anyone who needs quick and accurate frequency measurements.

Download on the App Store

Screenshots

From low-frequency signals to high-frequency audio measurement.

Low Frequency Mode

Detect low-frequency signals down to 50 Hz

High Frequency Mode

Measure frequencies up to 20 kHz

Note Detection

Real-time frequency, note and signal level display

About Screen

Built-in help, controls and feature guide

Features

Real-time frequency measurement
50 Hz to 20 kHz operating range
Automatic note identification
Signal level meter
One Shot capture mode
Auto calibration
High and Low frequency detection modes
Simple, easy-to-read interface

Who Uses FQC?

Musicians can identify notes and verify tuning frequencies.

Electronics enthusiasts can measure oscillators, tone generators, and audio circuits.

Students and hobbyists can explore the relationship between frequency and musical pitch.

Privacy

No tracking. No analytics. No advertising.

FQC processes audio locally on your device and does not collect or transmit personal information.

The microphone is used solely for frequency measurement and note identification.

No audio recordings are stored or uploaded.

Support

Questions, bug reports, feature requests, or feedback are always welcome.

Contact Support

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