# Decay calc vs Home screen countdown widgets

The clearest difference is rating: Home screen countdown widgets at 4.0 against Decay calc's 1.0. Decay calc's advantage is device support (3 vs 1). On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. Decay calc sells 1 one-off in-app purchase and Home screen countdown widgets sells 3 in-app purchases, starting at $0.99 per 7 days. Whichever you choose, the download price is not the number that matters.

Home screen countdown widgets holds the better App Store score, 4.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

Decay calc ships an update every 3 months, Home screen countdown widgets every 4 months. The most recent releases landed on October 8, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | Decay calc | Home screen countdown widgets |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.0 (1 ratings)](https://appshunter.io/ios/app/decay-calc/id1479526735/reviews) | **[4.0 (1 ratings)](https://appshunter.io/ios/app/home-screen-countdown-widgets/id6740415661/reviews)** |
| Number of ratings | 1 | 1 |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 4 months |
| Monetization | Free with in-app purchases | Freemium |
| Size | 27 MB | 50 MB |
| Requires iOS | **15.2** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 17+ | 4+ |
| Developer | [Alexey Baranov](https://appshunter.io/developer/1479526734) | [9arch OÜ](https://appshunter.io/developer/1723230625) |

## 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 |


### Home screen countdown widgets

[App page](https://appshunter.io/ios/app/home-screen-countdown-widgets/id6740415661)

Display customizable countdown and count-up widgets on your home screen for important events. Track birthdays, holidays, deadlines, habits, and more with personalized themes and icons. Unlock unlimited widgets and customization options with a premium upgrade.

**Highlights:** Countdown and count-up widgets, Home screen customization, Personalized themes and icons, Light and dark mode support, Habit and goal tracking, Unlimited widget creation (premium)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Countup Premium • Weekly | $0.99 | per 7 days |
| Countup Premium • Annually | $11.99 | per year |
| Lifetime | $5.99 | one-time |


## Frequently asked questions

### Is Decay calc free?

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

### Is Home screen countdown widgets free?

Home screen countdown widgets is free to download, with in-app purchases available.

### Which has better reviews, Decay calc or Home screen countdown widgets?

Home screen countdown widgets is rated higher. Decay calc averages 1.0 out of 5 from 1 ratings, while Home screen countdown widgets averages 4.0 from 1 ratings.

### Do Decay calc or Home screen countdown widgets have ads?

Neither Decay calc nor Home screen countdown widgets shows ads.

### Which is updated more often, Decay calc or Home screen countdown widgets?

Decay calc ships an update every 3 months, and Home screen countdown widgets every 4 months. Most recently, Decay calc was updated on October 8, 2026 and Home screen countdown widgets on October 4, 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.*