# Promethean vs DrPhos' Solution Calculator

The clearest difference is price: Promethean at Free against DrPhos' Solution Calculator's $0.99. Promethean also leads on in-app purchases (none vs 10) and iOS requirement (15.0 vs 17.2). DrPhos' Solution Calculator's advantage is update cadence (every 2 months vs every 4 months). On ads and device support there is nothing between them.

Promethean is free to download; DrPhos' Solution Calculator costs $0.99 up front. DrPhos' Solution Calculator sells 10 one-off in-app purchases. Promethean asks for nothing beyond the download.

Promethean ships an update every 4 months, DrPhos' Solution Calculator every 2 months. The most recent releases landed on October 16, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Promethean | DrPhos' Solution Calculator |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[2.5 (59 ratings)](https://appshunter.io/ios/app/promethean/id1447288595/reviews)** | — |
| Number of ratings | **59** | — |
| Positive reviews | 17.6% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 months** |
| Monetization | Free | — |
| Size | 66 MB | 15 MB |
| Requires iOS | **15.0** | 17.2 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Promethean](https://appshunter.io/developer/321367877) | [Monte L Helm](https://appshunter.io/developer/1715082616) |

## What reviewers say

### Promethean

[App page](https://appshunter.io/ios/app/promethean/id1447288595)

This app facilitates classroom collaboration by allowing students and teachers to interact with interactive panels wirelessly. IT administrators can also manage panel enrollment and updates. It offers screen sharing and access to training resources.

**Highlights:** Wireless screen sharing, Panel management for IT admins, Access to training materials, Student-teacher interaction, Panel enrollment and naming

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

**In-app purchases:** none


### DrPhos' Solution Calculator

[App page](https://appshunter.io/ios/app/drphos-solution-calculator/id6478795025)

**Features:** macOS Compatibility

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| General Chemistry Naming | $0.99 | one-time |
| Molar Mass Calculator | $0.99 | one-time |
| Stoichiometry | $0.99 | one-time |
| Reaction Balancer | $0.99 | one-time |
| Solution Concentrations | $0.99 | one-time |
| pH Calculator | $0.99 | one-time |
| Kinetics | $0.99 | one-time |
| Quadratic Equation Solver | $0.99 | one-time |
| Science Calculator | $0.99 | one-time |
| Significant Figures Counter | $0.99 | one-time |


## Frequently asked questions

### Is Promethean free?

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

### Is DrPhos' Solution Calculator free?

DrPhos' Solution Calculator costs $0.99, and also offers in-app purchases.

### Do Promethean or DrPhos' Solution Calculator have ads?

Neither Promethean nor DrPhos' Solution Calculator shows ads.

### Which is updated more often, Promethean or DrPhos' Solution Calculator?

Promethean ships an update every 4 months, and DrPhos' Solution Calculator every 2 months. Most recently, Promethean was updated on October 16, 2026 and DrPhos' Solution Calculator on October 7, 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.*