# Atomus HD vs F.A.S.T baby

The clearest difference is price: F.A.S.T baby at Free against Atomus HD's $3.99. Atomus HD's advantage is rating (4.8 vs 3.3) and update cadence (every 3 months vs every 55 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

F.A.S.T baby is free to download; Atomus HD costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Atomus HD holds the better App Store score, 4.8 against 3.3. That said, the two scores are not equally well evidenced: Atomus HD has 60 ratings behind it against 11, so its average is the more settled of the two.

Atomus HD ships an update every 3 months, F.A.S.T baby every 55 months. The most recent releases landed on October 30, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Atomus HD | F.A.S.T baby |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | **[4.8 (60 ratings)](https://appshunter.io/ios/app/atomus-hd/id741515911/reviews)** | [3.3 (11 ratings)](https://appshunter.io/ios/app/fast-baby/id1217030601/reviews) |
| Number of ratings | **60** | 11 |
| Positive reviews | 90.1% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 55 months |
| Monetization | Paid | **Free** |
| Size | 63 MB | 1 MB |
| Requires iOS | 15.6 | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [SungLab Inc](https://appshunter.io/developer/1691666995) | [Philippe Zay](https://appshunter.io/developer/1200498230) |

## What reviewers say

### Atomus HD

[App page](https://appshunter.io/ios/app/atomus-hd/id741515911)

Experience a premium kinetic universe of light and motion with dynamic, evolving particle structures. This app offers a richer, more immersive visual experience perfect for creative focus, relaxation, or quiet exploration.

**Highlights:** Evolving light and motion structures, Richer particle density and flow, Smooth 60 FPS rendering, 10-finger multi-touch support, Adjustable particle settings, Multiple color modes, Ad-free experience

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none

**What reviewers like**

- ✨ Visually stunning graphics
- 🧘‍♀️ Relaxing and calming experience
- 🎨 Creative and mesmerizing visuals
- 🎶 Beautiful and soothing music
- 🎮 Addictive and engaging gameplay

**What reviewers complain about**

- ⏳ Can become boring after a while
- ❓ Lack of user manual/explanations
- 🎶 Music can be repetitive
- 💸 Some users feel it's a waste of money
- 🎛️ Limited customization options

**Reported bugs**

- App crashes with 11 fingers
- Orientation issues on tablets
- Music not working
- Sound stopped working
- App freezes after opening and exiting

**Requested features**

- User manual or explanations
- Ability to customize starting points
- Option to record or save favorite settings
- Ability to take screenshots
- More music tracks/playlists


### F.A.S.T baby

[App page](https://appshunter.io/ios/app/fast-baby/id1217030601)

This app offers a calming visual experience for babies and very young children with colorful, moving spiral patterns. Tapping the screen generates new spirals, or they change automatically after a brief pause, providing a simple and engaging display.

**Highlights:** Tap to generate new spirals, Automatic spiral changes, Simple full-screen interface, Designed for young children, Colorful moving patterns

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Atomus HD free?

Atomus HD costs $3.99, with no in-app purchases.

### Is F.A.S.T baby free?

F.A.S.T baby is free to download, with no in-app purchases.

### Which has better reviews, Atomus HD or F.A.S.T baby?

Atomus HD is rated higher. Atomus HD averages 4.8 out of 5 from 60 ratings, while F.A.S.T baby averages 3.3 from 11 ratings.

### Do Atomus HD or F.A.S.T baby have ads?

Neither Atomus HD nor F.A.S.T baby shows ads.

### Which is updated more often, Atomus HD or F.A.S.T baby?

Atomus HD ships an update every 3 months, and F.A.S.T baby every 55 months. Most recently, Atomus HD was updated on October 30, 2026 and F.A.S.T baby on October 24, 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.*