# Periodacity vs Science 8

The clearest difference is rating: Science 8 at 5.0 against Periodacity's 3.7. Science 8 also leads on iOS requirement (11.0 vs 16.1). Periodacity's advantage is update cadence (every 3 weeks vs every 3 months). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Science 8 holds the better App Store score, 5.0 against 3.7. Both are backed by a comparable volume of ratings — 3 and 2 respectively.

Periodacity ships an update every 3 weeks, Science 8 every 3 months. The most recent releases landed on June 5, 2026 and August 19, 2026 respectively.

## The numbers

| Metric | Periodacity | Science 8 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.7 (3 ratings)](https://appshunter.io/ios/app/periodacity/id612368742/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/science-8/id1082583626/reviews)** |
| Number of ratings | **3** | 2 |
| Positive reviews | 75.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 3 months |
| Monetization | Free | Free |
| Size | 5 MB | 32 MB |
| Requires iOS | 16.1 | **11.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Jesse Spencer](https://appshunter.io/developer/612368745) | [IdeateGames](https://appshunter.io/developer/446654404) |

## What reviewers say

### Periodacity

[App page](https://appshunter.io/ios/app/periodacity/id612368742)

This app provides comprehensive reference information for all known elements on the periodic table. It's designed for chemists and chemistry students seeking quick access to element data.

**Highlights:** Complete periodic table data, Information on all known elements, Designed for chemists, Aimed at chemistry students, Reference tool

**Features:** macOS Compatibility

**In-app purchases:** none


### Science 8

[App page](https://appshunter.io/ios/app/science-8/id1082583626)

This app offers interactive tools and practice tests to help middle school students visualize and understand key science concepts. It includes simulations for density, molecular activity, and population dynamics, along with practice tests covering various science subjects.

**Highlights:** Interactive molecular activity demonstration, Density and buoyancy simulation, Comprehensive science practice tests, Category building exercises, Statistics exploration tool, Food web population dynamics simulation

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Periodacity free?

Periodacity is free to download, with no in-app purchases.

### Is Science 8 free?

Science 8 is free to download, with no in-app purchases.

### Which has better reviews, Periodacity or Science 8?

Science 8 is rated higher. Periodacity averages 3.7 out of 5 from 3 ratings, while Science 8 averages 5.0 from 2 ratings.

### Do Periodacity or Science 8 have ads?

Neither Periodacity nor Science 8 shows ads.

### Which is updated more often, Periodacity or Science 8?

Periodacity ships an update every 3 weeks, and Science 8 every 3 months. Most recently, Periodacity was updated on June 5, 2026 and Science 8 on August 19, 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.*