Frequently asked questions

Hertzy is a beautifully simple sound app for iPhone. You can dial in any frequency, choose a tone mode, and layer ambient soundscapes like rain or ocean — to help you focus, relax, or fall asleep.

Pure tones are a single steady frequency. Binaural beats play slightly different frequencies in each ear (best with headphones) so your brain perceives a rhythmic beat. Isochronic pulses turn a single tone on and off at a set rate, so they work without headphones too.

No. Hertzy is a wellness and relaxation tool, not a medical device. Its tones are not intended to diagnose, treat, cure, or prevent any condition, including ADHD. The effects of binaural beats are not conclusively proven. For medical concerns, please consult a qualified professional.

Not always. Pure tones, isochronic pulses, and ambient sounds all work over your phone speaker. Binaural beats are the exception — they rely on a different tone in each ear, so headphones are required for them to work as intended.

Rain, ocean, wind, and stream recordings, plus white, pink, and brown noise. You can play them on their own or layer them underneath a tone, and set a sleep timer to fade everything out.

Yes. Whenever you find a frequency and mode you love, save it. Your saved tones stay on your device and, if you have iCloud enabled, sync privately through your own iCloud — they are never uploaded to us.

Yes, Hertzy is free to download and supported by ads. If you'd prefer an ad-free experience, you can make a one-time “Remove Ads” in-app purchase.

It's a one-time, non-consumable purchase handled entirely by Apple's App Store. We never see your payment details. You can restore the purchase on any device signed in with the same Apple ID.

As little as possible. There are no accounts, and we don't collect your name, email, or contacts. The only data that leaves your device is anonymous, aggregated crash reports and usage statistics that help us keep the app stable. See the Privacy Policy for full details.

Hertzy is built for iPhone and requires iOS 18 or later.

Go to iOS Settings → Privacy & Security → Tracking and turn off tracking for Hertzy. You'll still see ads — they'll just be less personalized.

Email support@timkunst.nl with any questions, feedback, or support requests.