Frequency Counter+ Hz FFT

Kyu-Hee Jang · Utilities

3.3 6 ratings Free

Chart standing · US

Not currently charting in this storefront.

What changed · US

Listing changes AppTracker has observed for this app in this storefront — new versions, price moves, rating shifts, and store copy.

Aug 26, 2026
Rating ★ 3.67 → 3.33
Aug 26, 2026
New version 1.0.34 → 1.0.41

The Hum reading is now a true 0.01 Hz measurement: the app times the mains waveform across about a hundred cycles instead of rounding to a tenth. Stopping the tuner or the ultrasonic sweep no longer flashes a full-screen ad under your finger. Thanks for the reviews and feedback!

Price & rating history · US

Reconstructed from the listing changes AppTracker has observed in this storefront, so each line starts at the first change on record.

Average rating history over the observed period. 3.4 3.5 3.6 Aug 26 18:40 Aug 27 07:47 Aug 27 20:54 Aug 28 10:00 Aug 28 23:07

Average rating

Ratings breakdown · US

The star breakdown behind this app's rating in this storefront.

5★ 50% 3
4★ 0% 0
3★ 17% 1
2★ 0% 0
1★ 33% 2

Screenshots

About

Frequency Counter+ turns your iPhone into a precise audio analyzer with four purpose-built modes. Measure the dominant frequency of any sound, tune an instrument, read motor RPM by ear, or check the stability of your 50/60 Hz mains. FOUR MODES • Music — instrument tuner showing note name (A4, F#5) and cents off pitch (A4=440 Hz). • Motor — RPM displayed first, with hints for 1500/1800/3000/3600 RPM standards. • Hum — 50/60 Hz mains lock with deviation in ±0.01 Hz. • Auto — Hz reading with closest musical note or mains harmonic shown live. WHAT'S NEW • Measurement History — every reading is auto-saved with a 7-day trend chart and insights like "+12% vs your 7-day average". • Notes & Favorites — add a note ("fridge", "room 1") and star to any saved reading. • Compare Mode — pick two saved measurements and view the difference side by side. • Calibration Offset — fine-tune your microphone in ±0.1 Hz steps. • Share Result — share your current frequency reading as an image. • CSV Export — share all your measurements as CSV for spreadsheets. CORE FEATURES • Precise dominant frequency measurement (Hz) • Large multimeter-style digital display • Automatic 50/60 Hz mains hum detection with lock indicator • Instant Hz-to-RPM conversion • Waveform and amplitude visualization • Microphone calibration FOR MUSICIANS · AUDIO ENGINEERS · ELECTRICIANS · MECHANICS · HVAC TECHS · INDUSTRIAL DIAGNOSTICS Available in 14 languages.

What's new · 1.0.41

The Hum reading is now a true 0.01 Hz measurement: the app times the mains waveform across about a hundred cycles instead of rounding to a tenth. Stopping the tuner or the ultrasonic sweep no longer flashes a full-screen ad under your finger. Thanks for the reviews and feedback!

Details

DeveloperKyu-Hee Jang
ReleasedMar 2026
UpdatedJul 2026
Version1.0.41
Size70.8 MB
RequiresiOS 17.0 or later
Age rating17+
LanguagesEnglish
PriceFree
Categories UtilitiesProductivity
Bundle IDcom.simonj.frequencycounter