# Sync Hemispheres > App for brainwave entrainment using binaural beats and ambient sounds. (iPhone/iPad app by John Paul Grigsby.) - Source: https://appshunter.io/ios/app/sync-hemispheres/id6755691128 (this page in markdown: same URL + `.md`) - Developer: [John Paul Grigsby](https://appshunter.io/developer/1696719802) - Category: Lifestyle, Health & Fitness - Price: Free - Rating: 5.00/5 from 3 App Store ratings · 2 written reviews indexed - Age rating: 4+ - Requires: iOS 16.6 · 138 MB - Languages: English - Released: 2025-11-25 - Data updated: 2026-06-01 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/sync-hemispheres/id6755691128/reviews.md ## What is Sync Hemispheres? The brain produces electrical rhythms known as brainwaves. Different frequencies correlate with different mental states: deep sleep (Delta), lucid dreaming (Theta), relaxation (Alpha), active thinking (Beta), and peak focus (Gamma). Binaural beats work by playing two slightly different frequencies in each ear. The brain interprets the difference between them as a third beat frequency and gradually begins to synchronize with it. This is known as the frequency-following response. EEG studies show that both hemispheres work together when processing binaural beats, and that the brain’s electrical activity often shifts toward the difference frequency. This process is known as brainwave entrainment. Imagine two separate sound waves emitting from two different speakers. You can picture them expanding outward like concentric ripples as they collide in space. That point of collision creates what sounds like a pulse or beat. Isolate the two frequencies to your left and right ears. There is still a perceived rhythm where the waves differ, but not from a physical collision. This perceived beat is your brain interpreting the difference between the two tones. This naturally engages auditory pathways across both hemispheres. My name is John Grigsby (GRIGS). I am a musician, animator, sound designer, and I created this app. Sync Hemispheres is based on many years of work with sound, visuals, music, lucid dreaming techniques, and low-frequency cognitive entrainment. It is designed to help explore deeper rest, better focus, simultaneous use of both brain hemispheres, dream states, and self-guided mental awareness using controlled brainwave stimulation. The “Brainwaves” and “Brainwaves Timer” sections are dedicated to different ways of experiencing this phenomenon. The “Brainwaves” section lets you select different brainwave states with a slider and six presets. This includes five brainwave states, and one randomized Qigong state reflecting traditional Qigong flow and natural rhythmic drift. The “Brainwaves Timer” section lets you choose a starting and ending brainwave state, and how long you want your mind to gradually move from one to the other. These pages should be used with headphones. There is also an “Ambient Sounds” section. These include white noise, ocean waves, and meditative looping drones. A Tone slider lets you adjust the sound color. These ambient loops can be used on their own or blended with low-frequency binaural beats using the “Binaural Beats Blend” slider. This Ambient Sounds page can be enjoyed through the phone’s built-in speaker, external speakers, or with headphones if you prefer. To experience the full binaural-beat effect, use headphones. When listening with headphones, keep volume at a comfortable level and avoid excessively loud settings. Also, thanks to NASA for the use of their amazing satellite photography, which I used for some of the background imagery. ©2025 John Paul Grigsby — All Rights Reserved ## Key features - Binaural beat generation - Adjustable brainwave frequencies - Timed brainwave transitions - Ambient soundscapes - Brainwave state presets - Binaural beats and ambient sound blending ## Recent user reviews (2 of 2) All indexed reviews: https://appshunter.io/ios/app/sync-hemispheres/id6755691128/reviews.md ### 5/5 — Incredible *2025-12-05* I love this app! ### 5/5 — Amazing Sleep Aid *2025-11-27* This app is amazing for sleep and relaxation. Love that theres a binaural beats option as well as white noise. Being able to combine the two is genius. And the fact that it’s free with no in app purchases is a huge plus. ## Frequently asked questions about Sync Hemispheres ### What is Sync Hemispheres? Sync Hemispheres is a lifestyle app designed to help users explore different mental states through binaural beats and ambient sounds. It utilizes brainwave entrainment techniques to promote rest, focus, and dream states. ### How does Sync Hemispheres work? The app plays two slightly different frequencies in each ear, creating a perceived third beat frequency. Your brain synchronizes with this frequency, a process called brainwave entrainment, to influence mental states. ### What brainwave states can I explore with Sync Hemispheres? You can select from five brainwave states (Delta, Theta, Alpha, Beta, Gamma) and a randomized Qigong state. You can also set timers to gradually transition between states. ### Can I use Sync Hemispheres without headphones? While the full binaural beat effect is best experienced with headphones, the Ambient Sounds section can be enjoyed through your phone's speaker or external speakers. ### Is Sync Hemispheres free to use? Yes, Sync Hemispheres is available for free. There are no in-app purchases or advertisements mentioned. ### What devices does Sync Hemispheres support? Currently, Sync Hemispheres is supported on iPhone devices. It was last updated on January 26, 2026, with version 1.3.4. ### What is the age rating for Sync Hemispheres? Sync Hemispheres has an age rating of 4+, making it suitable for a wide range of users interested in its features. ### What do users think of Sync Hemispheres? Based on the available data, Sync Hemispheres has a perfect rating of 5.0 stars from 3 ratings, indicating a very positive user sentiment. ## Version history (last 5 releases) ### 1.3.7 — 2026-04-24 Reliable Brainwaves Timer playback for uninterrupted listening across all pages. ### 1.3.4 — 2026-01-26 a few minor adjustments ### 1.3.3 — 2026-01-09 Improved soundscape and binaural beats balance, background playback, and Bluetooth audio reliability ### 1.3.2 — 2025-12-08 refined audio behavior, visuals, & scalability ### 1.3.0 — 2025-12-05 Enhanced brainwave transitions, smoother visuals, and refined audio behavior ## More apps by John Paul Grigsby - [PALINGENESIS](https://appshunter.io/ios/app/palingenesis/id6467540178) All apps by John Paul Grigsby: https://appshunter.io/developer/1696719802 ## Related topics [sync hemispheres](https://appshunter.io/ios/topics/sync-hemispheres) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-01.*