# RTB2 vs PFT Spirometry

The clearest difference is update cadence: RTB2 at every 5 days against PFT Spirometry's every 2 weeks. RTB2 also leads on iOS requirement (15.1 vs 18). On price, ads, in-app purchases 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 and PFT Spirometry sells 2 in-app purchases, starting at $7.99 per month. Whichever you choose, the download price is not the number that matters.

RTB2 ships an update every 5 days, PFT Spirometry every 2 weeks. The most recent releases landed on June 17, 2026 and September 12, 2026 respectively.

## The numbers

| Metric | RTB2 | PFT Spirometry |
| --- | --- | --- |
| 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 | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 5 days** | Every 2 weeks |
| Monetization | Freemium | — |
| Size | 46 MB | 8 MB |
| Requires iOS | **15.1** | 18 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 17+ |
| Developer | [Bbytetechworks LLC](https://appshunter.io/developer/1844731958) | [ABHISHEK KUMAR](https://appshunter.io/developer/1877547879) |

## What reviewers say

### 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 |


### PFT Spirometry

[App page](https://appshunter.io/ios/app/pft-spirometry/id6787568741)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PFT Premium Monthly | $7.99 | per month |
| PFT Premium Yearly | $79.99 | per year |


## Frequently asked questions

### Is RTB2 free?

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

### Is PFT Spirometry free?

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

### Do RTB2 or PFT Spirometry have ads?

Neither RTB2 nor PFT Spirometry shows ads.

### Which is updated more often, RTB2 or PFT Spirometry?

RTB2 ships an update every 5 days, and PFT Spirometry every 2 weeks. Most recently, RTB2 was updated on June 17, 2026 and PFT Spirometry on September 12, 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.*