# R2R vs ∫dx

The clearest difference is update cadence: ∫dx at monthly against R2R's every 3 months. R2R's advantage is iOS requirement (10.3 vs 15.1). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. R2R sells 1 one-off in-app purchase and ∫dx sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

R2R ships an update every 3 months, ∫dx monthly. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | R2R | ∫dx |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (9 ratings)](https://appshunter.io/ios/app/r2r-advanced-chemistry/id1268437563/reviews)** | — |
| Number of ratings | **9** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Monthly** |
| Monetization | Free with in-app purchases | — |
| Size | 151 MB | 42 MB |
| Requires iOS | **10.3** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [James Styles](https://appshunter.io/developer/1537953716) | [PRANEEL AGRAWAL](https://appshunter.io/developer/1868893039) |

## What reviewers say

### R2R

[App page](https://appshunter.io/ios/app/r2r-advanced-chemistry/id1268437563)

This educational app helps students revise chemistry topics by asking targeted questions. It identifies weak areas and allows for random or topic-specific practice. An optional upgrade provides over 500 additional questions.

**Highlights:** Targeted chemistry questions, Identifies weak revision topics, Random and topic-specific practice, Exam board tailoring, Optional extra question packs

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Extra Questions Pack | $0.99 | one-time |


### ∫dx

[App page](https://appshunter.io/ios/app/dx-a-level-maths-practice/id6758026965)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| dx Premium Monthly | $4.99 | per month |
| dx Premium Annual | $12.99 | per year |


## Frequently asked questions

### Is R2R free?

R2R is free to download, with in-app purchases available.

### Is ∫dx free?

∫dx is free to download, with in-app purchases available.

### Do R2R or ∫dx have ads?

Neither R2R nor ∫dx shows ads.

### Which is updated more often, R2R or ∫dx?

R2R ships an update every 3 months, and ∫dx monthly. Most recently, R2R was updated on November 3, 2026 and ∫dx on October 31, 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.*