# Physical Constants vs Protein Guide

The clearest difference is rating: Protein Guide at 4.8 against Physical Constants's 3.3. Protein Guide also leads on ads (none vs shown) and review sentiment (50% vs 33%). On price, update cadence, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Protein Guide holds the better App Store score, 4.8 against 3.3. That said, the two scores are not equally well evidenced: Protein Guide has 45 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 33% of Physical Constants's written reviews are positive against 50% of Protein Guide's.

Both ship on a similar rhythm, roughly every 9 months. The most recent releases landed on November 1, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | Physical Constants | Protein Guide |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.3 (3 ratings)](https://appshunter.io/ios/app/physical-constants-ml/id837679891/reviews) | **[4.8 (45 ratings)](https://appshunter.io/ios/app/protein-guide/id1375157917/reviews)** |
| Number of ratings | 3 | **45** |
| Positive reviews | 33.3% of reviews | **50.0% of reviews** |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 9 months | Every 9 months |
| Monetization | Ad-supported | **Free** |
| Size | 25 MB | 224 MB |
| Requires iOS | 12.0 | **11.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Takuya Ishikawa](https://appshunter.io/developer/468311118) | [Axton Pitt](https://appshunter.io/developer/957165645) |

## What reviewers say

### Physical Constants

[App page](https://appshunter.io/ios/app/physical-constants-ml/id837679891)

Access a comprehensive list of physical constants, organized by category for easy searching. This app supports all AppStore languages and allows users to report corrections via email.

**Highlights:** Physical constants database, Categorized by topic, Search functionality, Multi-language support, User feedback for corrections

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

**In-app purchases:** none


### Protein Guide

[App page](https://appshunter.io/ios/app/protein-guide/id1375157917)

Explore the intricate stages of protein structure with detailed diagrams, explanations, and animations. This app serves as a valuable reference for both beginners and experienced individuals, offering insights into unique properties and biological functions.

**Highlights:** Detailed diagrams of protein structure, Explanations of protein stages, Animations of protein structures, Information on unique properties and functions, Example proteins demonstrating structural aspects, ClassKit integration for teachers

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Physical Constants free?

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

### Is Protein Guide free?

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

### Which has better reviews, Physical Constants or Protein Guide?

Protein Guide is rated higher. Physical Constants averages 3.3 out of 5 from 3 ratings, while Protein Guide averages 4.8 from 45 ratings.

### Do Physical Constants or Protein Guide have ads?

Physical Constants shows ads; Protein Guide does not.

### Which is updated more often, Physical Constants or Protein Guide?

Physical Constants ships an update every 9 months, and Protein Guide every 9 months. Most recently, Physical Constants was updated on November 1, 2026 and Protein Guide on November 2, 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.*