Frequency Counter+ Hz FFT is a multi-mode audio analysis tool for iOS and Android that measures frequency, tunes instruments, and detects power-line hum.
The App DNA
What makes this app unique?
The app removes the need for expensive, dedicated hardware by using the device microphone to provide quick, on-the-go diagnostic readings for electricians and musicians.
For Professionals and hobbyists in audio engineering, electrical work, and music who require precise frequency analysis tools.
What does it look like?
Key features
Locks onto power-line frequency with 0.01 Hz deviation precision, establishing category authority for electricians and HVAC technicians.
Auto-saves frequency readings with 7-day trend charts and comparative insights, creating a retention loop for monitoring diagnostics over time.
Displays note names and pitch deviation in cents, broadening the user base to musicians to increase ad-impression volume.
How much does it cost?
Monetization relies entirely on ad-inventory generated by free-tier usage, with no current IAP or subscription gates.
Velocity
Active developmentUX improvementsperformanceplatform expansionShow more...
Frequency Counter+ Hz FFT currently ships at an active cadence, averaging 1.5 releases per week based on the recent three-version window. Development is focused on technical precision and UX improvements, specifically addressing cross-platform stability for Chromebooks and tablets. The latest update also demonstrates a shift in monetization UX by removing intrusive full-screen ads during active measurement sessions. The development trend is stable, with a clear focus on refining core utility features.
Who built it?
Kyu-Hee Jang
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What do users think recently?
Fresh user feedback skews frustrated. Users appreciate the core functionality provides a useful tool for measuring hair clipper revolutions per minute.
How are ratings & reviews evolving?
What users say, by theme
- The core functionality provides a useful tool for measuring hair clipper revolutions per minute
- Users report: Full screen advertisements and fake security warnings disrupt the user experience and create distrust
8 of 8 recent reviews analyzed · limited sample · Frustrated overall
Read the full review analysisUnlock 2 more frustration themes and 1 user request, each backed by review evidence.
Access the full report for freeCompetition
Competitive landscape for Frequency Counter+ Hz FFT
How's the Utilities market?
Frequency Counter+ Hz FFT maintains a 3.33 rating across 60 total platform reviews. The lack of IAP or subscription gates limits monetization to ad-inventory, which currently conflicts with the professional utility promise.
Read the market outlookThe rivals identified
Unlock the deeper market read.
Access the full report for freeThe Analyst's Read
Key takeaways for Frequency Counter+ Hz FFT
Where is it heading?
The diagnostic utility market is consolidating around tools that offer reliable, ad-free experiences for professionals. Frequency Counter+ Hz FFT remains exposed due to its current monetization strategy, which directly conflicts with the precision required by its target audience.
- Users report: Intrusive ad patterns and deceptive security alerts drive negative sentiment, which compounds the churn pressure already visible in the low rating.
- The recent update cadence (three releases in two weeks) demonstrates active feature investment, which could stabilize the app if functional bugs are resolved.
The SWOT
- 50/60 Hz mains hum detection with 0.01 Hz precision establishes category authority for electrical diagnostics
- Measurement history with 7-day trend charts creates a retention loop for professional diagnostics
- Implementing a Pro-tier subscription to remove ads would align monetization with the professional user base
- Adding manual frequency selection controls would improve spectrum display accuracy for professional users
Next best moves
Migrate from full-screen ads to a Pro-tier subscription because ad-driven monetization is the #1 complaint theme → increase user trust and LTV
+ 1 more prioritized moveThe counter-intuitive read
The app's reliance on ad-inventory is a strategic error…
Read the full takeSince the last report: The developer has pivoted its monetization strategy from ad-inventory reliance to a planned Pro-tier subscription model to address persistent user distrust. This shift in development focus replaces previous plans for new measurement modes with a priority on subscription infrastructure.
Bottom line
Transitioning to a subscription-based model would resolve the distrust caused by intrusive ads, allowing the app to serve its professional audience without the friction that currently drives negative sentiment.
Unlock 3 critical frictions, 2 market threats, 1 more prioritized move and the analyst’s take.
Access the full report for freeFAQ
Is Frequency Counter+ Hz FFT suitable for professional electrical work?
Does the app have intrusive advertisements?
What are the limitations of the current frequency detection?
Sources
- [1] Play Store listing, source
Report last updated