# RelativityTheory vs Periodic

The clearest difference is update cadence: RelativityTheory at every 3 weeks against Periodic's every 5 weeks. RelativityTheory also leads on price ($0.99 vs $1.99). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

RelativityTheory costs $0.99 and Periodic $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

RelativityTheory ships an update every 3 weeks, Periodic every 5 weeks. The most recent releases landed on September 13, 2026 and August 16, 2026 respectively.

## The numbers

| Metric | RelativityTheory | Periodic |
| --- | --- | --- |
| Price | **$0.99** | $1.99 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 5 weeks |
| Size | 6 MB | 31 MB |
| Requires iOS | **14.4** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Takao Akatsu](https://appshunter.io/developer/1530946331) | [Om Prakash Chapagain](https://appshunter.io/developer/1618620262) |

## What reviewers say

### RelativityTheory

[App page](https://appshunter.io/ios/app/relativitytheory/id1620999874)

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

**In-app purchases:** none


### Periodic

[App page](https://appshunter.io/ios/app/periodic-table-elements-pro/id1628646759)

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

**In-app purchases:** none


## Frequently asked questions

### Is RelativityTheory free?

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

### Is Periodic free?

Periodic costs $1.99, with no in-app purchases.

### Do RelativityTheory or Periodic have ads?

Neither RelativityTheory nor Periodic shows ads.

### Which is updated more often, RelativityTheory or Periodic?

RelativityTheory ships an update every 3 weeks, and Periodic every 5 weeks. Most recently, RelativityTheory was updated on September 13, 2026 and Periodic on August 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.*