# ABG Expert vs Respi

The clearest difference is in-app purchases: ABG Expert at none against Respi's 3. ABG Expert also leads on review sentiment (100% vs 88%) and iOS requirement (13.0 vs 16.6). Respi's advantage is update cadence (weekly vs every 5 months) and ratings volume (118 vs 9). On price, rating, ads and monetization model there is nothing between them.

Both are free to download. Respi sells 3 one-off in-app purchases. ABG Expert asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.8 for ABG Expert against 4.7 for Respi. That said, the two scores are not equally well evidenced: Respi has 118 ratings behind it against 9, so its average is the more settled of the two. Written reviews are what separate them: 100% of ABG Expert's written reviews are positive against 88% of Respi's.

ABG Expert ships an update every 5 months, Respi weekly. The most recent releases landed on June 9, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | ABG Expert | Respi |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (9 ratings)](https://appshunter.io/ios/app/abg-expert/id885575488/reviews)** | [4.7 (118 ratings)](https://appshunter.io/ios/app/respi-rate/id1508183194/reviews) |
| Number of ratings | 9 | **118** |
| Positive reviews | **100.0% of reviews** | 87.5% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Weekly** |
| Monetization | Free | Free |
| Size | 2 MB | 29 MB |
| Requires iOS | **13.0** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 17+ |
| Developer | [Brian Dale Vander Werf MD Inc](https://appshunter.io/developer/1521935908) | [medappear s.r.o.](https://appshunter.io/developer/1508183193) |

## What reviewers say

### ABG Expert

[App page](https://appshunter.io/ios/app/abg-expert/id885575488)

This medical tool provides accurate and flexible acid-base analysis for healthcare professionals. It offers detailed explanations, customizable ranges, and advanced features like anion gap correction and A-a gradient adjustments for various patient conditions and locations.

**Highlights:** Validated accuracy with real-world testing, Plausibility checks for physiologically impossible data, Automatic anion gap correction with albumin, Detailed explanations with equations, Separate or combined analysis of ABG, anion gap, A-a gradient, Customizable normal ranges for anion gap and delta gap, Age and barometric pressure adjustments for A-a gradient, Support for SI and non-SI units, Color-coded results and differential diagnoses, Adjustments for chronic respiratory conditions

**Features:** macOS Compatibility

**In-app purchases:** none


### Respi

[App page](https://appshunter.io/ios/app/respi-rate/id1508183194)

This app assists healthcare professionals in accurately measuring a patient's respiratory rate. It uses an innovative algorithm and a simple button press to calculate breaths per minute, accounting for user reaction time for precise results. Designed for regular breathing patterns, it ensures accuracy within 95% ± 1 breath/min.

**Highlights:** Accurate respiratory rate calculation, Innovative algorithm, Simple one-button interface, Accounts for user reaction time, Ensures 95% ± 1 breath/min accuracy, Designed for regular breathing patterns

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 7-Day Free Pro Trial | Free | one-time |
| Lifetime Pro — Intro Offer | $9.99 | one-time |
| Lifetime Pro | $12.99 | one-time |


## Frequently asked questions

### Is ABG Expert free?

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

### Is Respi free?

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

### Which has better reviews, ABG Expert or Respi?

ABG Expert is rated higher. ABG Expert averages 4.8 out of 5 from 9 ratings, while Respi averages 4.7 from 118 ratings.

### Do ABG Expert or Respi have ads?

Neither ABG Expert nor Respi shows ads.

### Which is updated more often, ABG Expert or Respi?

ABG Expert ships an update every 5 months, and Respi weekly. Most recently, ABG Expert was updated on June 9, 2026 and Respi on September 22, 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.*