# Decay Tree

> Visualizes nuclear decay chains, modes, half-lives, and particle emissions. (iPhone/iPad app by Gustaf Holst.)

- Source: https://appshunter.io/ios/app/decay-tree/id1066023546 (this page in markdown: same URL + `.md`)
- Developer: [Gustaf Holst](https://appshunter.io/developer/1066023545)
- Category: Education, Utilities
- Price: Free with in-app purchases
- Rating: 4.14/5 from 7 App Store ratings · 2 written reviews indexed
- Age rating: 4+
- Requires: iOS 12.0 · 53 MB
- Languages: English
- Released: 2016-01-29
- Data updated: 2026-07-07
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/decay-tree/id1066023546/reviews.md

## What is Decay Tree?

Decay Tree visualizes the whole decay chain for almost any known nuclide. Decay modes and half-lives are graphically shown. In addition, details like spin, specific activity, and emitted particles are tabulated and graphed.

## Key features

- Visualizes decay chains
- Graphical display of decay modes
- Graphical display of half-lives
- Tabulated details of spin, specific activity, emitted particles
- Graphs of spin, specific activity, emitted particles

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Remove Ads | $1.99 | one-time |
| Radiation Table | $0.99 | one-time |


## Recent user reviews (2 of 2)

All indexed reviews: https://appshunter.io/ios/app/decay-tree/id1066023546/reviews.md

### 4/5 — Info display

*2024-01-26, version 2.2*

Nice little app, but some of the isotopes have tabulated decay energies and others have graphical spectra. There doesn’t appear to be a logic of which has what or an obvious way to switch between them (which would be great).

### 5/5 — Great app for decay tree information

*2020-06-08, version 2.0*

The new version is great, and I have unlocked the data tables in the app. There’s a small bug, in that dark mode prevents the visibility of some isotope names, easily. Hope the developer corrects this, other than that it’s great for a rad nerd. Developer has confirmed an update will address this very minor issue. This is a great tool for decay tree information, and the additional data is useful for my applications. Great work

## Frequently asked questions about Decay Tree

### What is Decay Tree?

Decay Tree is an educational application that visually represents the entire decay chain for nearly any known nuclide. It graphically displays decay modes and half-lives, along with detailed tabulated and graphed information on spin, specific activity, and emitted particles.

### What learning methodology does Decay Tree use?

Decay Tree employs a visual and data-driven learning methodology. It uses graphical representations and detailed tables to help users understand complex nuclear decay processes and their associated properties.

### How does Decay Tree track user progress?

Decay Tree does not explicitly mention progress tracking features. Its primary function is to provide visualization and data for educational purposes rather than structured learning paths or progress monitoring.

### Does Decay Tree offer certifications?

Decay Tree is an educational tool for visualizing nuclear decay and does not offer any formal certifications upon completion of its content.

### What devices is Decay Tree available on?

Decay Tree is available on iPhone, iPad, and iPod devices. It is designed for iOS users interested in nuclear science education.

### How often is Decay Tree updated?

The latest version of Decay Tree is 2.2, last updated on April 16, 2022. This indicates a relatively infrequent update cycle for the application.

### Does Decay Tree have ads?

Yes, Decay Tree contains advertisements. As it is a free application with in-app purchases, advertisements are present to support its development and distribution.

### What is the age rating for Decay Tree?

Decay Tree has an age rating of 4+. This suggests it is suitable for a wide audience, including younger learners, though its complex subject matter may be best understood by older students or adults.

## Version history (last 5 releases)

### 2.2 — 2022-04-16

In this version the database has been expanded to include decay modes taking multiple steps at a time. New features also include:
- A new hierarchal view mode
- A branching ratio slider, to highlight the most probable decay paths
- Continuous spectrum graphs
- Spontaneous fission fragments for some isotopes

In addition, some visual bugs have been fixed.

### 2.1 — 2020-06-10

Implemented Dark Mode

### 2.0 — 2020-06-07

New in 2.0:
- 450+ isotopes added to the database
- table of emitted particles added with energy and emissions per decay
- isotope properties added: spin, parity, branching ratio, specific activity and natural abundance

### 1.1 — 2016-02-12

New in 1.1:
- Added color and symbol explanations to first page and through a quickly accessible info-button
- Polished the nuclide details text
- Remapped the half-life colouring scheme
- Fixed trees that grew out of the screen
- Fixed nuclide overlaps
- Fixed decay mode symbol misplacements
- Fixed slow loading and crashes on bigger trees

### 1.0 — 2016-01-29

No release notes.

## Apps similar to Decay Tree

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [ENEC 360](https://appshunter.io/ios/app/enec-360/id1315730030) | 5.0 (2) | Free | Education |
| [Nuclide Chart](https://appshunter.io/ios/app/nuclide-chart/id6756217497) | — | Free | Education |
| [Atomizer AR: Quantum Chemistry](https://appshunter.io/ios/app/atomizer-ar-quantum-chemistry/id6449015706) | 4.0 (3) | Free | Education |
| [Chemy: Chemistry Companion](https://appshunter.io/ios/app/chemy-chemistry-companion/id1542390153) | 5.0 (6) | Free | Education |
| [Isotope Browser](https://appshunter.io/ios/app/isotope-browser/id943890538) | 4.8 (25) | Free | Education |
| [Chart of the Nuclides](https://appshunter.io/ios/app/chart-of-the-nuclides/id1529624218) | 4.9 (16) | Free | Education |

## Related topics

[isotope](https://appshunter.io/ios/topics/isotope) · [isotope browser](https://appshunter.io/ios/topics/isotope-browser) · [isotopes](https://appshunter.io/ios/topics/isotopes) · [thorium](https://appshunter.io/ios/topics/thorium)

---

*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 2026-07-07.*