# Decay calc vs Timecon

The clearest difference is ads: Decay calc at none against Timecon's shown. Decay calc also leads on update cadence (every 3 months vs every 12 months). Timecon's advantage is iOS requirement (13.0 vs 15.2). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Decay calc sells 1 one-off in-app purchase and Timecon sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

Decay calc ships an update every 3 months, Timecon every 12 months. The most recent releases landed on September 21, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Decay calc | Timecon |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/decay-calc/id1479526735/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 3 months** | Every 12 months |
| Monetization | Free with in-app purchases | — |
| Size | 27 MB | 28 MB |
| Requires iOS | 15.2 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [Alexey Baranov](https://appshunter.io/developer/1479526734) | [kota tada](https://appshunter.io/developer/1658942612) |

## What reviewers say

### Decay calc

[App page](https://appshunter.io/ios/app/decay-calc/id1479526735)

This tool calculates the decay of radioactive isotopes over time, considering half-life for accurate activity predictions. It's useful in nuclear medicine, environmental monitoring, and radiation safety for handling and disposal of materials.

**Highlights:** Radioactive isotope decay calculation, Half-life integration, Activity prediction, Decay constant determination, Radiation dose calculation

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Radio calc | $0.99 | one-time |


### Timecon

[App page](https://appshunter.io/ios/app/timecon-time-conversion-tool/id6743643430)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Ad-free for 1 month | $4.99 | per month |
| Ad-free for 1 year | $49.99 | per year |


## Frequently asked questions

### Is Decay calc free?

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

### Is Timecon free?

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

### Do Decay calc or Timecon have ads?

Timecon shows ads; Decay calc does not.

### Which is updated more often, Decay calc or Timecon?

Decay calc ships an update every 3 months, and Timecon every 12 months. Most recently, Decay calc was updated on September 21, 2026 and Timecon on October 7, 2026.

---

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