# Periodic vs DrPhos Science Calculator

The clearest difference is in-app purchases: Periodic at none against DrPhos Science Calculator's 10. Periodic also leads on iOS requirement (15.1 vs 18.5). DrPhos Science Calculator's advantage is ads (none vs shown) and update cadence (every 3 weeks vs every 5 weeks). On price and device support there is nothing between them.

Both are free to download. DrPhos Science Calculator sells 10 one-off in-app purchases. Periodic asks for nothing beyond the download.

Periodic ships an update every 5 weeks, DrPhos Science Calculator every 3 weeks. Both last shipped on November 5, 2026.

## The numbers

| Metric | Periodic | DrPhos Science Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/drphos-science-calculator/id6747954398/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 5 weeks | **Every 3 weeks** |
| Monetization | — | Free with in-app purchases |
| Size | 35 MB | 11 MB |
| Requires iOS | **15.1** | 18.5 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Om Prakash Chapagain](https://appshunter.io/developer/1618620262) | [Monte L Helm](https://appshunter.io/developer/1715082616) |

## What reviewers say

### Periodic

[App page](https://appshunter.io/ios/app/periodic-table-elements/id1628647298)

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

**In-app purchases:** none


### DrPhos Science Calculator

[App page](https://appshunter.io/ios/app/drphos-science-calculator/id6747954398)

This scientific calculator app is designed for high school and college students, as well as everyday science tasks. It offers precise control over significant figures and displays results in both normal and scientific formats. The interface is user-friendly with clear controls and helpful error messages, supporting offline use on iPhone and iPad.

**Highlights:** Standard arithmetic and chained calculations, Scientific-notation and exponent entry, Adjustable significant-figure formatting, Normal and scientific result displays, Clear error handling, Offline operation, iPhone and iPad support

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Quadratic Equation Solver | $0.99 | one-time |
| Solution Concentrations | $0.99 | one-time |
| Molar Mass Calculator | $0.99 | one-time |
| Ionic Compound Builder | $0.99 | one-time |
| Reaction Balancer | $0.99 | one-time |
| Naming Compounds | $0.99 | one-time |
| pH Calculator | $0.99 | one-time |
| Stoichiometry | $0.99 | one-time |
| Kinetics | $0.99 | one-time |
| Significant Figures Counter | $0.99 | one-time |


## Frequently asked questions

### Is Periodic free?

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

### Is DrPhos Science Calculator free?

DrPhos Science Calculator is free to download, with in-app purchases available.

### Do Periodic or DrPhos Science Calculator have ads?

Periodic shows ads; DrPhos Science Calculator does not.

### Which is updated more often, Periodic or DrPhos Science Calculator?

Periodic ships an update every 5 weeks, and DrPhos Science Calculator every 3 weeks. Most recently, Periodic was updated on November 5, 2026 and DrPhos Science Calculator on November 5, 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.*