# Hz Frequency by Lamda vs sol

The clearest difference is update cadence: sol at every 2 days against Hz Frequency by Lamda's every 9 days. sol also leads on rating (5.0 vs 4.7). Hz Frequency by Lamda's advantage is ratings volume (21 vs 3) and device support (3 vs 1). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Hz Frequency by Lamda sells 5 in-app purchases, starting at $4.99 per month and sol sells 2 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

sol holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Hz Frequency by Lamda has 21 ratings behind it against 3, so its average is the more settled of the two.

Hz Frequency by Lamda ships an update every 9 days, sol every 2 days. The most recent releases landed on November 8, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | Hz Frequency by Lamda | sol |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (21 ratings)](https://appshunter.io/ios/app/hz-frequency-by-lamda/id6747421302/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/sol-dreams/id6760870952/reviews)** |
| Number of ratings | **21** | 3 |
| Positive reviews | 75.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 9 days | **Every 2 days** |
| Monetization | Freemium | Freemium |
| Size | 168 MB | 14 MB |
| Requires iOS | **14.0.0** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Jehan Radwan](https://appshunter.io/developer/1820159651) | [Zachary Hogan](https://appshunter.io/developer/1886553260) |

## What reviewers say

### Hz Frequency by Lamda

[App page](https://appshunter.io/ios/app/hz-frequency-by-lamda/id6747421302)

This app offers precision Hz frequency soundscapes designed to promote inner harmony, clarity, and calm. It features binaural beats and various admired frequencies embedded in relaxing music, with interactive visual meditations to support stress relief and sleep.

**Highlights:** Precision Hz frequency programs, Binaural Beats, Interactive 3D scenes, Includes 432 Hz, 528 Hz, and solfeggio frequencies, Stress relief and relaxation support, Short interactive exercises

**Features:** Family Sharing

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Premium | $4.99 | per month |
| Monthly Premium Standard | $8.99 | per month |
| Annual | $19.99 | per year |
| Annual Premium | $44.00 | per year |
| Lifetime | $110.99 | one-time |


### sol

[App page](https://appshunter.io/ios/app/sol-dreams/id6760870952)

This app uses AI to map your emotions to solfeggio frequencies and pair them with personalized sleep playlists. Track your emotional history and receive tailored frequency readings that evolve over time. Enjoy curated Spotify playlists designed to enhance your sleep experience.

**Highlights:** Emotional word check-ins, AI-powered frequency readings, Curated Spotify sleep playlists, Progressive reading history, Premium daily check-ins, Partner mode

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Premium | $3.99 | per month |
| Yearly Premium | $29.99 | per year |


## Frequently asked questions

### Is Hz Frequency by Lamda free?

Hz Frequency by Lamda is free to download, with in-app purchases available.

### Is sol free?

sol is free to download, with in-app purchases available.

### Which has better reviews, Hz Frequency by Lamda or sol?

sol is rated higher. Hz Frequency by Lamda averages 4.7 out of 5 from 21 ratings, while sol averages 5.0 from 3 ratings.

### Do Hz Frequency by Lamda or sol have ads?

Neither Hz Frequency by Lamda nor sol shows ads.

### Which is updated more often, Hz Frequency by Lamda or sol?

Hz Frequency by Lamda ships an update every 9 days, and sol every 2 days. Most recently, Hz Frequency by Lamda was updated on November 8, 2026 and sol on November 5, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*