# TeachFX vs DrPhos' pH Calculator

The clearest difference is price: TeachFX at Free against DrPhos' pH Calculator's $0.99. TeachFX also leads on rating (5.0 vs 3.7) and in-app purchases (none vs 11). On update cadence, ads, device support and iOS requirement there is nothing between them.

TeachFX is free to download; DrPhos' pH Calculator costs $0.99 up front. DrPhos' pH Calculator sells 11 one-off in-app purchases. TeachFX asks for nothing beyond the download.

TeachFX holds the better App Store score, 5.0 against 3.7. That said, the two scores are not equally well evidenced: TeachFX has 21 ratings behind it against 3, so its average is the more settled of the two.

TeachFX ships an update weekly, DrPhos' pH Calculator every 10 days. The most recent releases landed on September 7, 2026 and June 4, 2026 respectively.

## The numbers

| Metric | TeachFX | DrPhos' pH Calculator |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[5.0 (21 ratings)](https://appshunter.io/ios/app/teachfx/id1329178826/reviews)** | [3.7 (3 ratings)](https://appshunter.io/ios/app/drphos-ph-calculator/id6477762321/reviews) |
| Number of ratings | **21** | 3 |
| Positive reviews | 75.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Weekly** | Every 10 days |
| Monetization | **Ad-supported** | Free with in-app purchases |
| Size | 65 MB | 15 MB |
| Requires iOS | **16.4** | 17.2 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [TeachFX](https://appshunter.io/developer/1294178492) | [Monte L Helm](https://appshunter.io/developer/1715082616) |

## What reviewers say

### TeachFX

[App page](https://appshunter.io/ios/app/teachfx/id1329178826)

This tool helps educators gain insights into classroom learning dynamics by capturing and analyzing student-teacher conversations. It provides visible evidence of student engagement and instructional practices, fostering reflection and professional growth. The app is designed for privacy and personalization.

**Highlights:** Classroom talk ratio analysis, Academic language tracking, Questioning technique evaluation, Think time and turn-taking observation, Student participation patterns, Personalized and private data

**In-app purchases:** none


### DrPhos' pH Calculator

[App page](https://appshunter.io/ios/app/drphos-ph-calculator/id6477762321)

This tool instantly calculates pH, pOH, and ion concentrations for strong and weak acids and bases. It supports molarity and scientific notation, ensuring accurate results for general chemistry problems.

**Highlights:** Calculate pH, pOH, [H⁺], or [OH⁻], Handles strong and weak acids/bases, Supports Ka and Kb values, Built-in molarity and scientific notation, Automatic pH + pOH = 14, Clean, focused layout

**Features:** macOS Compatibility

**In-app purchases (11)**

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


## Frequently asked questions

### Is TeachFX free?

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

### Is DrPhos' pH Calculator free?

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

### Which has better reviews, TeachFX or DrPhos' pH Calculator?

TeachFX is rated higher. TeachFX averages 5.0 out of 5 from 21 ratings, while DrPhos' pH Calculator averages 3.7 from 3 ratings.

### Do TeachFX or DrPhos' pH Calculator have ads?

Neither TeachFX nor DrPhos' pH Calculator shows ads.

### Which is updated more often, TeachFX or DrPhos' pH Calculator?

TeachFX ships an update weekly, and DrPhos' pH Calculator every 10 days. Most recently, TeachFX was updated on September 7, 2026 and DrPhos' pH Calculator on June 4, 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.*