# Critical Thinking Concepts vs DrPhos' Solution Calculator

The clearest difference is price: Critical Thinking Concepts at Free against DrPhos' Solution Calculator's $0.99. On update cadence, ads, in-app purchases and device support there is nothing between them.

Critical Thinking Concepts is free to download; DrPhos' Solution Calculator costs $0.99 up front. Critical Thinking Concepts sells 2 in-app purchases, starting at $3.99 per month and DrPhos' Solution Calculator sells 10 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 8, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Critical Thinking Concepts | DrPhos' Solution Calculator |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[4.7 (37 ratings)](https://appshunter.io/ios/app/critical-thinking-concepts/id6446604872/reviews)** | — |
| Number of ratings | **37** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | Free with in-app purchases | — |
| Size | 35 MB | 15 MB |
| Requires iOS | 18.0 | **17.2** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Anthony Harvey](https://appshunter.io/developer/1478197285) | [Monte L Helm](https://appshunter.io/developer/1715082616) |

## What reviewers say

### Critical Thinking Concepts

[App page](https://appshunter.io/ios/app/critical-thinking-concepts/id6446604872)

This app is an interactive study companion that teaches core concepts, methods, and terminology of critical thinking. It helps users develop analytical and reasoning skills for navigating complex issues effectively. Features include Q&A, swipe cards, a visual feed, audio playback, and study statistics.

**Highlights:** Question & Answer format, Swipe card learning, Visual learning feed, Audio player for lessons, Study statistics tracking, Offline usability

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| All Access Monthly | $3.99 | per month |
| All Access Annual | $7.99 | per year |


### 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 Critical Thinking Concepts free?

Critical Thinking Concepts is free to download, with in-app purchases available.

### Is DrPhos' Solution Calculator free?

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

### Do Critical Thinking Concepts or DrPhos' Solution Calculator have ads?

Neither Critical Thinking Concepts nor DrPhos' Solution Calculator shows ads.

### Which is updated more often, Critical Thinking Concepts or DrPhos' Solution Calculator?

Critical Thinking Concepts ships an update every 2 months, and DrPhos' Solution Calculator every 2 months. Most recently, Critical Thinking Concepts was updated on October 8, 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.*