# PP+ Archimedes Principle vs Bacteria 3D

The clearest difference is price: Bacteria 3D at Free against PP+ Archimedes Principle's $1.99. Bacteria 3D also leads on update cadence (weekly vs every 29 months) and device support (3 vs 1). On ads and in-app purchases there is nothing between them.

Bacteria 3D is free to download; PP+ Archimedes Principle costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

PP+ Archimedes Principle ships an update every 29 months, Bacteria 3D weekly. The most recent releases landed on February 1, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | PP+ Archimedes Principle | Bacteria 3D |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | — | **[4.6 (58 ratings)](https://appshunter.io/ios/app/bacteria-3d/id1168927717/reviews)** |
| Number of ratings | — | **58** |
| Positive reviews | — | 70.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 29 months | **Weekly** |
| Monetization | — | Free |
| Size | 111 MB | 115 MB |
| Requires iOS | 18.0 | **8.0** |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Polyhedron Learning Media, Inc.](https://appshunter.io/developer/458882328) | [MOZAIK Education Ltd.](https://appshunter.io/developer/1064850236) |

## What reviewers say

### PP+ Archimedes Principle

[App page](https://appshunter.io/ios/app/pp-archimedes-principle/id622367686)

**Features:** macOS Compatibility

**In-app purchases:** none


### Bacteria 3D

[App page](https://appshunter.io/ios/app/bacteria-3d/id1168927717)

Explore biology through interactive 3D animations of bacteria in various shapes. This app offers a dynamic learning experience with pre-set views, narration, quizzes, and VR mode. It's designed for students but engaging for all ages.

**Highlights:** Interactive 3D bacteria models, Rotatable and zoomable scenes, Predefined navigation views, Walk mode for exploration, Narrations and animations, Animated quizzes, VR mode support

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is PP+ Archimedes Principle free?

PP+ Archimedes Principle costs $1.99, with no in-app purchases.

### Is Bacteria 3D free?

Bacteria 3D is free to download, with no in-app purchases.

### Do PP+ Archimedes Principle or Bacteria 3D have ads?

Neither PP+ Archimedes Principle nor Bacteria 3D shows ads.

### Which is updated more often, PP+ Archimedes Principle or Bacteria 3D?

PP+ Archimedes Principle ships an update every 29 months, and Bacteria 3D weekly. Most recently, PP+ Archimedes Principle was updated on February 1, 2026 and Bacteria 3D on October 15, 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.*