Frequency Analyzer vs Stackis RPN
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Frequency Analyzer
Transform your device into a professional audio analysis tool with advanced FFT analysis, SPL monitoring, and detailed visualizations. Record, analyze, and export audio data with precision calibration and multiple weighting filters.
- Real-time FFT analysis
- Calibrated SPL measurements
- 32-bit float audio recording
- Synchronized video recording
- Spectrogram and octave band analysis
- Export WAV, CSV, images, and videos
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Transform your device into a professional-grade audio analysis suite with industry-leading 32-bit float processing, precision calibration tools, and comprehensive visualization capabilities. PROFESSIONAL ACOUSTIC MEASUREMENT • Real-time FFT analysis with configurable window sizes up to 4096 points • Reference SPL measurement with calibrated sound pressure level monitoring • Professional microphone correction with frequency-specific calibration curves • Reference tone calibration for precise frequency measurements • Configurable time averaging (0-1000ms) for stable, accurate readings • Industry-standard weighting filters: dBA, dBC, dBZ, and linear magnitude • Multiple window functions: Hanning, Hamming, Blackman ADVANCED VISUALIZATION MODES • High-resolution spectrum analyzer with peak detection • Real-time waveform display • Professional spectrogram • Octave band analysis • Amplitude tracking over time • Total level monitoring with min/max/average statistics POWERFUL RECORDING & ANALYSIS • High-quality 32-bit float audio recording and playback • Synchronized video recording with audio analysis overlay • Event tracking system with timestamped notes • Playback synchronization with all recorded events and measurements • Location mapping for environmental noise surveys • Export capabilities: WAV audio, CSV data, high-resolution images and videos PRECISION DECIBEL MEASUREMENT • Calibrated SPL measurements with reference level adjustment • Real-time dB monitoring with peak hold functionality • Statistical analysis: Leq, Lmax • Configurable time averaging (0-1000ms) • Frequency-weighted noise exposure calculations • Exposure calculator for NIOSH and OSHA IDEAL FOR PROFESSIONALS • Acousticians and audio engineers • Environmental noise consultants • Musicians and sound designers • Room acoustics optimization • Industrial noise monitoring • Educational and research applications • Live sound reinforcement • Building acoustics assessment Download now and unlock the full spectrum of acoustic measurement capabilities. DISCLAIMER This is a consumer application designed for general audio analysis and educational purposes. It is not a certified measurement instrument and should not be used where legally compliant or certified measurements are required. For professional acoustic assessments requiring traceable calibration or regulatory compliance, we recommend using an external calibrated measurement microphone with certified sound level meters. EULA: https://frequency-analyzer.com/terms-and-conditions/
Stackis RPN
A calculator designed for users who prefer Reverse Polish Notation (RPN). It offers a familiar interface for RPN users and includes support for duodecimal calculations.
- RPN calculation style
- Duodecimal (dozenal) support
- Familiar interface for RPN users
- Simple and pleasant user experience
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This is an RPN calculator in the style of, for instance, old HP models. It will feel familiar if you are used to RPN, otherwise it will probably be a little confusing at first. It's not programmable and it doesn't try to mimic older hardware; it's just meant to be a pleasant calculator for those who prefer to use RPN. Also, if you want to perform calculations in duodecimal (dozenal), this app is for you!
Screenshots
Verdict
The clearest difference is review sentiment: Stackis RPN at 100% against Frequency Analyzer's 10%. Stackis RPN also leads on rating (5.0 vs 4.5) and monetization model (free vs free with in-app purchases). Frequency Analyzer's advantage is ratings volume (166 vs 2). On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Frequency Analyzer sells 11 in-app purchases, starting at $2.99 per 7 days and Stackis RPN sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
Stackis RPN holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Frequency Analyzer has 166 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 10% of Frequency Analyzer's written reviews are positive against 100% of Stackis RPN's.
Frequency Analyzer ships an update every 8 days, Stackis RPN every 4 days. The most recent releases landed on September 26, 2026 and June 2, 2026 respectively.
| Parameter | Frequency Analyzer | Stackis RPN |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (166 ratings) | 5.0 (2 ratings) — better |
| Positive reviews | 10.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 166 — better | 2 |
| Update frequency | Every 8 days | Every 4 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone | iPhone, iPod — better |
| Requires iOS | 17.2 — better | 17.6 |
| Further details — not scored | ||
| Size | 35 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | Manfred Kuegel | Skimra |
Customer experience
Frequency Analyzer
Stackis RPN
In-app purchases
Frequency Analyzer
- Frequency Analyzer Pro Weekly3 Days trial$2.997 Days
- Frequency Analyzer Pro Monthly7 Days trial$3.991 Month
- Frequency Analyzer Pro Monthly$3.991 Month
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- Frequency Analyzer Pro Monthly7 Days trial$4.991 Month
- Frequency Analyzer Pro Monthly$4.991 Month
- Frequency Analyzer Pro Monthly3 Days trial$4.991 Month
- Frequency Analyzer Pro Annual7 Days trial$29.991 Year
- Frequency Analyzer Pro Annual7 Days trial$44.991 Year
- Frequency Analyzer Pro Annual$44.991 Year
- Frequency Analyzer Pro Annual3 Days trial$44.991 Year
- Pro access for lifetime$89.99
Stackis RPN
- Advanced Mode$1.99
Questions
Is Frequency Analyzer free?
Is Stackis RPN free?
Which has better reviews, Frequency Analyzer or Stackis RPN?
Do Frequency Analyzer or Stackis RPN have ads?
Which is updated more often, Frequency Analyzer or Stackis RPN?
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