Comparison

Frequency Generator vs PhantomGram

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Frequency Generator

Generate precise audio tones for sleep, focus, and relaxation. Explore a wide frequency range, shape waveforms, and access presets like Solfeggio frequencies. An optional Pro upgrade unlocks all features.

Highlights
  • Wide frequency range (1 Hz - 22,000 Hz)
  • Multiple waveforms (sine, square, sawtooth, triangle)
  • Background audio playback
  • Solfeggio frequencies and musical notes
  • Binaural beats and isochronic tones
  • Saved and pinned tone presets
  • Lock-screen and Control Center controls
Features
Read full description

Frequency Generator turns your iPhone into a precise, studio-clean tone source — for sleep, focus, relaxation, and sound exploration. Dial in any frequency from a deep 1 Hz rumble to a 22,000 Hz shimmer, shape its character, and press play. WIND DOWN AND SLEEP Mask traffic, chatter, and a restless mind with smooth white, pink, or brown noise. Start it playing, lock your phone, and let it run all night in the background. FIND YOUR FOCUS Drop into deep work with binaural beats and isochronic tones, or let steady noise blur out distractions around you. Made for studying, writing, and long concentration sessions. RELAX, MEDITATE, RESTORE Play the tones people reach for to unwind — including 432 Hz, 528 Hz, and the full set of Solfeggio frequencies — as a calm backdrop for meditation, breathwork, or simply slowing down. PLAY ANY NOTE Sound any pitch across nine octaves (C0–B8) as a clean reference tone, and set your concert pitch anywhere from 432 to 446 Hz. Ideal for tuning by ear, training your ear to intervals, or checking a note on the fly. EXPLORE THE FULL SPECTRUM Sweep all the way up to 22 kHz to hear the high and ultrasonic frequencies your ears, headphones, and speakers can reproduce. Shape the timbre with sine, square, sawtooth, or triangle waveforms. PRECISE, EFFORTLESS CONTROL Set an exact frequency down to the hertz, fine-tune it on a smooth slider, and switch sounds instantly. No clutter, no setup — just the tone you want, the moment you want it. PICK UP WHERE YOU LEFT OFF Every tone you play is saved to Recents. Pin your favorites, give them names, and replay any setup with a single tap. KEEPS PLAYING Full background audio with lock-screen and Control Center controls, so your sound stays with you while you get on with everything else. Frequency Generator is free to use, with an optional Pro upgrade that unlocks every waveform and noise color, binaural beats and isochronic tones, and the Solfeggio and musical-note presets. Privacy Policy: https://frequency-analyzer.com/privacy-policy-frequency-generator/ Terms of Use: https://frequency-analyzer.com/terms-and-conditions-frequency-generator/

About

PhantomGram

Features
Read full description

PhantomGram — Paint the Airwaves Spectrum painting for amateur radio. Encode any image as audio and transmit it through your radio — the picture appears directly on the receiver's SDR waterfall display. No special decoder needed at the other end. The image IS the spectrum. HOW IT WORKS Spectrum painting exploits the way SDR waterfall displays work. A waterfall shows radio frequency on one axis and time on the other, with colour representing signal strength. PhantomGram converts each row of your image into a carefully crafted audio signal where pixel brightness maps to tone amplitude and pixel position maps to frequency. When transmitted via SSB radio, the receiver's waterfall reassembles the picture automatically. TRANSMIT Select an image from your photo library or camera, or use the built-in test patterns (bars, gradient, checkerboard, concentric circles). Choose a resolution preset — from QUICK (80×64, under 4 seconds) to SLOW (640×256, maximum detail). Adjust the frequency range with the dual-knob slider. The image is encoded automatically and a TX preview shows exactly what the receiver's waterfall will display. Tap SEND to transmit. RECEIVE Tap START and point your iPhone's microphone at a radio speaker or connect via audio cable. The live FFT spectrum shows incoming signal energy across the frequency band. Below it, a continuous waterfall display reconstructs the image in real time as it arrives. Adjust gain to brighten weak signals. Save decoded images to the built-in log for later viewing and sharing. FEATURES • Encode images as spectrum painting audio via inverse FFT with random phase • Adjustable frequency range (0–10,000 Hz) with sensible defaults for SSB radio (200–2,800 Hz) • Four resolution presets: QUICK, STANDARD, DETAIL, SLOW • Real-time receive decode with live FFT spectrum display • SDR-style waterfall colourmap (black → blue → cyan → green → yellow → orange → red) • Optional header tone for transmission synchronisation • Received image log with save and share • Phosphor CRT aesthetic — green or amber display themes • Zero external dependencies — pure Swift and Accelerate framework DSP • iPhone speaker and microphone — no additional hardware required TYPICAL USE Connect your iPhone's headphone output to your radio's microphone input (or simply hold the phone near the mic). Tune your radio to an appropriate frequency, key the transmitter, and tap SEND. Anyone monitoring that frequency with an SDR receiver will see your image appear on their waterfall display. For receiving, tune your radio to the transmission frequency, connect the radio's speaker output to your iPhone (or use acoustic coupling), and tap START. FREQUENCY GUIDANCE • STANDARD (200–2,800 Hz) — fits within normal SSB audio passband • NARROW (500–2,500 Hz) — safe for most radio mic inputs • WIDE (200–3,500 Hz) — only if your radio passes full audio bandwidth • SSTV-FIT (1,500–2,300 Hz) — coexists with SSTV activity Part of the Phosphor suite, sister app to PhosphorRTTY and PhosphorCW, amongst others. REMEMEBR: TRANSMIT ON LICENSED FREQUENCIES ONLY.

Screenshots

Frequency Generator4 screens
PhantomGram4 screens

Verdict

The call

The clearest difference is price: Frequency Generator at Free against PhantomGram's $0.99. Frequency Generator also leads on update cadence (monthly vs every 6 months) and iOS requirement (18.3 vs 26.2). PhantomGram's advantage is in-app purchases (none vs 2). On ads 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

CostPrice · In-app purchases · Ads · Monetization

Frequency Generator is free to download; PhantomGram costs $0.99 up front. Frequency Generator sells 2 in-app purchases, starting at $4.99 per 7 days. PhantomGram asks for nothing beyond the download.

UpkeepUpdate frequency

Frequency Generator ships an update monthly, PhantomGram every 6 months. The most recent releases landed on October 19, 2026 and October 14, 2026 respectively.

Scorecard4 real differences · 6 level
Frequency Generator versus PhantomGram: the parameters behind the verdict, then further details
ParameterFrequency GeneratorPhantomGram
PriceFree — better$0.99
Rating4.7 (20 ratings) — better—
Positive reviews50.0% of reviews—
Number of ratings20 — better—
Update frequencyMonthly — betterEvery 6 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemium—
DevicesiPhone, iPad — betteriPhone
Requires iOS18.3 — better26.2
Further details — not scored
Size21 MB2 MB
Age rating4+4+
DeveloperManfred KuegelStuart Woolley

In-app purchases

2 purchases

Frequency Generator

Subscriptions2
  • Pro Weekly$4.997 Days
  • Pro Yearly7 Days trial$29.991 Year
None

PhantomGram

No in-app purchases

Questions

Is Frequency Generator free?
Frequency Generator is free to download, with in-app purchases available.
Is PhantomGram free?
PhantomGram costs $0.99, with no in-app purchases.
Do Frequency Generator or PhantomGram have ads?
Neither Frequency Generator nor PhantomGram shows ads.
Which is updated more often, Frequency Generator or PhantomGram?
Frequency Generator ships an update monthly, and PhantomGram every 6 months. Most recently, Frequency Generator was updated on October 19, 2026 and PhantomGram on October 14, 2026.

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