Comparison

Isochronic Tone Generator vs Quell

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

Head to head
About

Isochronic Tone Generator

Create precise rhythmic audio pulses for meditation, focus, or breathwork. Customize frequency, carrier tone, and waveform for a personalized auditory experience. Enjoy a calm interface with background audio support.

Highlights
  • 1-50 Hz pulse control
  • Adjustable carrier tone
  • Multiple waveform options
  • Depth and softness controls
  • Background audio support
  • Minimal visualizer
Features
Read full description

Isochronic Tone Generator is a focused audio tool for creating clean, precise isochronic pulse tones from 1 to 50 Hz. Set a pulse frequency, choose a carrier tone, shape the depth and softness, then start listening. The app includes simple presets for common listening ranges, multiple waveform options, haptic frequency adjustment on iPhone, background audio support, and a calm visual interface designed to stay out of the way. Use it for meditation, focus sessions, breathwork, experimentation, or any routine where a steady rhythmic tone helps you settle in. Features: - 1-50 Hz isochronic pulse control - Adjustable carrier tone - Sine, square, sawtooth, and triangle waveforms - Depth, softness, and volume controls - Presets for common frequency ranges - Background audio and Lock Screen controls on iPhone - Minimal visualizer with fluid themes Isochronic tones are rhythmic audio pulses. Use comfortable volume levels, take breaks, and do not use while driving or operating machinery.

About

Quell

Features
Read full description

Quell is a deep-focus app with one job: help you sit down and do one undivided thing. No streaks. No badges. No feed. You tap Begin, a calm arctic ring starts counting up, and a 40 Hz binaural beat plays underneath. When you are done, you end. That is the whole ritual. WHY 40 Hz 40 Hz is the gamma band — the brain rhythm tied to attention and memory, and the most-studied frequency in sound-based focus research. Quell generates it live: two pure tones, one slightly different in each ear, that your brain fuses into a single 40 Hz pulse. WHAT IT DOES - A 40 Hz binaural beat, generated live on your device. Two pure tones on a deep, warm carrier (130 Hz left, 170 Hz right). It needs stereo headphones to create the beat. - An optional coach voice. Short, grounded lines, spaced minutes apart, that nudge you back when your attention drifts. It is sports-psychology self-talk, not generic meditation, and it is a natural recorded voice, not a robotic one. - Optional music under the beat. Four moods of original, AI-generated tracks (lofi days, lofi night, global beats, ambient) that sit quietly beneath everything. Off by default. - A count-up timer. No fixed length, no pressure. The session lasts as long as you stay. THE SCIENCE, HONESTLY We lead with 40 Hz because the research is real — it is the gamma approach popularized on the Huberman Lab podcast. A 2022 meta-analysis found binaural beats gave a small but significant lift to attention and memory, and a 2025 study confirmed that a 40 Hz beat measurably entrains the brain while improving attention. But we will not oversell it: not every study agrees, and the effect varies from person to person. Treat the 40 Hz tone as a low-risk way to settle into deep work, not a guarantee. DESIGNED TO DISAPPEAR Quell is dark, still, and quiet on purpose. The only bright thing is the ring. It keeps playing while your screen is off, with controls on the lock screen, so you can put the phone down and work. PRIVATE BY DESIGN Everything runs on your device. No account, no sign-in, no tracking, no analytics, no servers. Your settings stay on your phone. FREE AND PAID The 40 Hz beat and the timer are free, forever. A single one-time purchase unlocks the music moods and the coach voice. Pay once, it is yours. No subscription. Quell. Quiet the noise.

Screenshots

Isochronic Tone Generator4 screens
Quell4 screens

Verdict

The call

Isochronic Tone Generator and Quell are too close to call on the numbers: across 5 compared parameters — price, ads, in-app purchases and device support among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

Both are free to download. Isochronic Tone Generator sells 1 one-off in-app purchase and Quell sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

ScorecardNo meaningful differences
Isochronic Tone Generator versus Quell: the parameters behind the verdict, then further details
ParameterIsochronic Tone GeneratorQuell
PriceFreeFree
Rating5.0 (2 ratings) — better—
Number of ratings2 — better—
Update frequency—Daily
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhone, MaciPhone, Mac
Requires iOS17.017.0
Further details — not scored
Size2 MB58 MB
Age rating4+4+
DeveloperNathan MuellerOleksandr Pavlov

In-app purchases

1 purchases

Isochronic Tone Generator

One-time1
  • Isochronic Themes$0.99
1 purchases

Quell

One-time1
  • Quell Unlock$9.99

Questions

Is Isochronic Tone Generator free?
Isochronic Tone Generator is free to download, with in-app purchases available.
Is Quell free?
Quell is free to download, with in-app purchases available.
Do Isochronic Tone Generator or Quell have ads?
Neither Isochronic Tone Generator nor Quell shows ads.

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