# Formulas +, your 4 collections vs Re

The clearest difference is price: Re at Free against Formulas +, your 4 collections's $3.99. Re also leads on in-app purchases (none vs 2) and update cadence (every 2 months vs every 4 months). On ads and device support there is nothing between them.

Re is free to download; Formulas +, your 4 collections costs $3.99 up front. Formulas +, your 4 collections sells 2 one-off in-app purchases. Re asks for nothing beyond the download.

Formulas +, your 4 collections ships an update every 4 months, Re every 2 months. The most recent releases landed on October 14, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | Formulas +, your 4 collections | Re |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Positive reviews | 38.5% of reviews | **50.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 months** |
| Monetization | Paid | **Free** |
| Size | 27 MB | 260 MB |
| Requires iOS | 12.0 | **10.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [app-solutions.de](https://appshunter.io/developer/550462608) | [Brandenburgische Technische Universitaet Cottbus-Senftenberg](https://appshunter.io/developer/626792264) |

## What reviewers say

### Formulas +, your 4 collections

[App page](https://appshunter.io/ios/app/formulas-plus-your-4-collections/id550462605)

This app consolidates essential formulas for mathematics, physics, chemistry, and technical subjects into a single, easy-to-use application. It features an intelligent search function and provides clear explanations and graphics to aid understanding.

**Highlights:** Consolidated formulas for multiple subjects, Intelligent search function, Explanations and graphics, Calculation function (In-App Purchase), User suggestion feature

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Basics Pack | $0.99 | one-time |
| Geometry/Stereometry Pack 1 | $0.99 | one-time |


### Re

[App page](https://appshunter.io/ios/app/reconstruction/id1479008884)

Step into a post-apocalyptic future where you join a network to save the world. Engage in quests, develop future technologies, and analyze your progress. Your contributions are vital to restoring balance.

**Highlights:** Quests in 4 game areas, Avatar customization, Environment analysis, Progress tracking, Background information videos, Glossary

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Formulas +, your 4 collections free?

Formulas +, your 4 collections costs $3.99, and also offers in-app purchases.

### Is Re free?

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

### Do Formulas +, your 4 collections or Re have ads?

Neither Formulas +, your 4 collections nor Re shows ads.

### Which is updated more often, Formulas +, your 4 collections or Re?

Formulas +, your 4 collections ships an update every 4 months, and Re every 2 months. Most recently, Formulas +, your 4 collections was updated on October 14, 2026 and Re on October 1, 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.*