Quell: Deep Focus

40 Hz sound for deep focus

Free · In‑App Purchases

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.

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Refreshed our App Store screenshots to show Focus for ADHD — the noise-forward focus mode for ADHD brains — plus breathing, felt-time markers, and the coach. No changes to the app itself in this version.

Version 1.2

The developer, Oleksandr Pavlov, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

    Privacy practices may vary, for example, based on the features you use or your age. Learn More

    Accessibility

    The developer has not yet indicated which accessibility features this app supports. Learn More

    Information

    Seller
    • Oleksandr Pavlov
    Size
    • 61.1 MB
    Category
    • Health & Fitness
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    • English
    Age Rating
    4+
    In-App Purchases
    Yes
    Copyright
    • © 2026 Quell LLC
  • Developer Website
  • Privacy Policy

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