frekvens vs FrequencyCat
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
frekvens
This app offers a unique frequency shifter and stereo delay effect. It utilizes single sideband modulation and an infinite impulse response filter for advanced audio manipulation. Additional features include high/low pass filters and an LFO for delay modulation.
- Frequency shifter
- Stereo delay
- High and low pass filter
- LFO for delay modulation
- Core MIDI CC input
- Audiobus and Inter-App Audio support
- Audio Unit extension
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Frekvens is a frequency shifter and delay effect. Unlike a pitch shifter all frequencies are shifted linearly and then fed back into itself using the stereo delay unit. The frequency shifting is achieved with single sideband modulation using a hilbert transform and an infinite impulse response filter for fast computations. Frekvens also comes with a high and low pass filter and a lfo for modulating the delay play head. - frequency shifter - high, low pass filter - stereo delay - core midi cc input - audiobus - inter app audio - audio unit extension - save, load
FrequencyCat
Transform your photos into unique sound art using advanced image-to-sound technology. Explore, enjoy, and share your creative audio-visual pieces. Embrace your inner artist and discover the unexpected.
- Morph images into sound art
- Create spectrogram oddities
- Share sound art creations
- Unique audio-visual experience
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Hide an image inside sound. FrequencyCat is a playful tool for exploring the connection between images, sound, and spectrograms. Choose an image, and FrequencyCat transforms it into a unique audio signal. Play the sound and view its spectrogram, and you’ll see the original image emerge again from the frequencies. With FrequencyCat, you can: - Turn images into sound - View audio spectrograms in real time - Play sounds and reveal the images hidden inside them - Explore how different images create different sounds - Discover the relationship between sound, frequency, and Fourier transforms in an intuitive way There’s no magic behind it. Just frequencies, phases, an inverse Fourier transform, and a little curiosity about sound. Whether you’re interested in acoustics, music, signal processing, or simply wondering what an image might sound like, FrequencyCat gives you a new way to explore. Pick an image. Hear what it sounds like.
Screenshots
Verdict
The clearest difference is price: FrequencyCat at Free against frekvens's $2.99. FrequencyCat also leads on review sentiment (100% vs 83%) and rating (5.0 vs 4.8). frekvens's advantage is update cadence (every 2 months vs every 40 months) and ratings volume (21 vs 1). On ads and in-app purchases 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
FrequencyCat is free to download; frekvens costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
FrequencyCat holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: frekvens has 21 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 83% of frekvens's written reviews are positive against 100% of FrequencyCat's.
frekvens ships an update every 2 months, FrequencyCat every 40 months. The most recent releases landed on October 12, 2026 and October 6, 2026 respectively.
| Parameter | frekvens | FrequencyCat |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 4.8 (21 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 83.3% of reviews | 100.0% of reviews — better |
| Number of ratings | 21 — better | 1 |
| Update frequency | Every 2 months — better | Every 40 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 11.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 3 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Erik Sigth | Xuesong Zhang |
Customer experience
frekvens
FrequencyCat
In-app purchases
frekvens
No in-app purchases
FrequencyCat
No in-app purchases









