# NxGen Peak Flow vs RTB2

The clearest difference is in-app purchases: NxGen Peak Flow at none against RTB2's 1. NxGen Peak Flow also leads on iOS requirement (12.0 vs 15.1). On price, ads and device support there is nothing between them.

Both are free to download. RTB2 sells 1 in-app purchase, starting at $2.99 per month. NxGen Peak Flow asks for nothing beyond the download.

## The numbers

| Metric | NxGen Peak Flow | RTB2 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/rtb2-respiratory-reference/id6757658847/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | — | Every 5 days |
| Monetization | — | Freemium |
| Size | 55 MB | 46 MB |
| Requires iOS | **12.0** | 15.1 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 17+ | 4+ |
| Developer | [Safey Medical Devices Ltd](https://appshunter.io/developer/1551912769) | [Bbytetechworks LLC](https://appshunter.io/developer/1844731958) |

## What reviewers say

### NxGen Peak Flow

[App page](https://appshunter.io/ios/app/nxgen-peak-flow/id6727005153)

**In-app purchases:** none


### RTB2

[App page](https://appshunter.io/ios/app/rtb2-respiratory-reference/id6757658847)

This medical reference app provides respiratory therapists and students with essential clinical tools. It features ventilator mode guides, therapy calculators, and oxygen guidance in a clean, organized format for quick access in critical care settings.

**Highlights:** Ventilator mode reference guides, Respiratory therapy clinical calculators, Oxygen device guidance, Structured respiratory care information, Fast clinical review format, Advanced calculators (Pro)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| RTB2 Pro | $2.99 | per month |


## Frequently asked questions

### Is NxGen Peak Flow free?

NxGen Peak Flow is free to download, with no in-app purchases.

### Is RTB2 free?

RTB2 is free to download, with in-app purchases available.

### Do NxGen Peak Flow or RTB2 have ads?

Neither NxGen Peak Flow nor RTB2 shows ads.

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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.*