# Stoichiometry vs Periodic

The clearest difference is price: Periodic at $1.99 against Stoichiometry's $2.99. Periodic also leads on iOS requirement (15.1 vs 17.1). On update cadence, ads, in-app purchases and device support there is nothing between them.

Stoichiometry costs $2.99 and Periodic $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Stoichiometry ships an update every 2 months, Periodic every 5 weeks. The most recent releases landed on October 29, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Stoichiometry | Periodic |
| --- | --- | --- |
| Price | $2.99 | **$1.99** |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 5 weeks** |
| Monetization | Paid | — |
| Size | 1 MB | 31 MB |
| Requires iOS | 17.1 | **15.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Roman Volinsky](https://appshunter.io/developer/977951850) | [Om Prakash Chapagain](https://appshunter.io/developer/1618620262) |

## What reviewers say

### Stoichiometry

[App page](https://appshunter.io/ios/app/stoichiometry/id1330949637)

This tool helps balance chemical reactions and calculate molar masses, moles, and actual masses of reactants and products. It supports various formula formats and can identify limiting reagents. Data can be sent to another app for gas phase calculations.

**Highlights:** Balance chemical reactions, Calculate molar masses, Determine moles and actual masses, Identify limiting reagents, Supports various formula formats, Integrates with Gas Phase Stoichiometry app

**Features:** 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 Stoichiometry free?

Stoichiometry costs $2.99, with no in-app purchases.

### Is Periodic free?

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

### Do Stoichiometry or Periodic have ads?

Neither Stoichiometry nor Periodic shows ads.

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

Stoichiometry ships an update every 2 months, and Periodic every 5 weeks. Most recently, Stoichiometry was updated on October 29, 2026 and Periodic on October 30, 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.*