# Radioactive Decay Simulator vs Radioactivity

The clearest difference is price: Radioactive Decay Simulator at Free against Radioactivity's $0.99. Radioactive Decay Simulator also leads on update cadence (every 17 months vs every 36 months) and device support (3 vs 1). On ads and in-app purchases there is nothing between them.

Radioactive Decay Simulator is free to download; Radioactivity costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Radioactive Decay Simulator ships an update every 17 months, Radioactivity every 36 months. The most recent releases landed on June 5, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | Radioactive Decay Simulator | Radioactivity |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[4.0 (1 ratings)](https://appshunter.io/ios/app/radioactive-decay-simulator/id959357000/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 17 months** | Every 36 months |
| Monetization | Free | — |
| Size | 20 MB | 52 MB |
| Requires iOS | **9.3** | 12.0 |
| Devices | **iPhone, iPad, iPod** | iPad |
| Age rating | 4+ | 4+ |
| Developer | [Alistair Shaw](https://appshunter.io/developer/959356999) | [www.ajaxmediatech.com](https://appshunter.io/developer/973768003) |

## What reviewers say

### Radioactive Decay Simulator

[App page](https://appshunter.io/ios/app/radioactive-decay-simulator/id959357000)

This educational tool simulates radioactive decay for a group of atoms. Users can choose preset atoms or input custom half-lives to observe decay in real-time graphs. The simulator allows for adjustments in atom count and speed for efficient analysis.

**Highlights:** Emulates radioactive decay, Select preset or custom atoms, Adjust atom count, Real-time decay graphs, Adjustable simulation speed

**Features:** macOS Compatibility

**In-app purchases:** none


### Radioactivity

[App page](https://appshunter.io/ios/app/radioactivity-physics/id1136130171)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Radioactive Decay Simulator free?

Radioactive Decay Simulator is free to download, with no in-app purchases.

### Is Radioactivity free?

Radioactivity costs $0.99, with no in-app purchases.

### Do Radioactive Decay Simulator or Radioactivity have ads?

Neither Radioactive Decay Simulator nor Radioactivity shows ads.

### Which is updated more often, Radioactive Decay Simulator or Radioactivity?

Radioactive Decay Simulator ships an update every 17 months, and Radioactivity every 36 months. Most recently, Radioactive Decay Simulator was updated on June 5, 2026 and Radioactivity on September 16, 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.*