# 23 Equations vs NU Open Day

The clearest difference is in-app purchases: NU Open Day at none against 23 Equations's 7. 23 Equations's advantage is iOS requirement (9.3 vs 15.1). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. 23 Equations sells 7 one-off in-app purchases. NU Open Day asks for nothing beyond the download.

23 Equations ships an update every 2 weeks, NU Open Day monthly. The most recent releases landed on June 1, 2026 and July 6, 2026 respectively.

## The numbers

| Metric | 23 Equations | NU Open Day |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/23-equations/id1451090127/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 47.6% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Monthly |
| Monetization | Free with in-app purchases | **Free** |
| Size | 143 MB | 115 MB |
| Requires iOS | **9.3** | 15.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Nick Whitehurst](https://appshunter.io/developer/1451090126) | [Newcastle University](https://appshunter.io/developer/558828803) |

## What reviewers say

### 23 Equations

[App page](https://appshunter.io/ios/app/23-equations/id1451090127)

Master GCSE and IGCSE Physics equations with interactive learning and practice questions. The app provides instant feedback, model answers, and timed challenges to improve recall and application. Teachers can create and monitor student tests for effective revision planning.

**Highlights:** Learn physics equations by heart, Practice questions with step-by-step help, Model answers for improvement, Timed challenges and games, Teacher-created tests for students, Monitor student progress and answers, Index card-style equation reference

**Features:** macOS Compatibility

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Individual: Extra features | $1.99 | one-time |
| School Room, 2022 Exams (S) | $39.99 | one-time |
| School Room, 2023 Exams (S) | $39.99 | one-time |
| School Room, 2022 Exams (M) | $69.99 | one-time |
| School Room, 2023 Exams (M) | $74.99 | one-time |
| School Room, 2022 Exams (L) | $99.99 | one-time |
| School Room, 2023 Exams (L) | $99.99 | one-time |


### NU Open Day

[App page](https://appshunter.io/ios/app/nu-open-day/id6737686175)

Navigate university life with this official companion app. Discover events, find buildings on an interactive map, and access live travel information. Explore accommodation options and stay updated with campus news.

**Highlights:** Personalized event planner, Interactive campus map with walking routes, Live travel information for buses and trains, Accommodation finder, University news and student tips blog

**In-app purchases:** none


## Frequently asked questions

### Is 23 Equations free?

23 Equations is free to download, with in-app purchases available.

### Is NU Open Day free?

NU Open Day is free to download, with no in-app purchases.

### Do 23 Equations or NU Open Day have ads?

Neither 23 Equations nor NU Open Day shows ads.

### Which is updated more often, 23 Equations or NU Open Day?

23 Equations ships an update every 2 weeks, and NU Open Day monthly. Most recently, 23 Equations was updated on June 1, 2026 and NU Open Day on July 6, 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.*