Comparison

ABG Expert vs ABGs NOW!

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

ABG Expert

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
Read full description

ABG Expert™ is simply the best acid-base analysis tool with features available in no other app. Designed and tested by practicing physicians, ABG Expert is trusted by medical professionals for unparalleled accuracy, flexibility, and power while remaining completely intuitive to use. Whether you are a physician, nurse, respiratory therapist, paramedic, or student, ABG Expert is your ideal acid base analysis app. Accuracy- • ABG Expert has been validated using extensive testing under real-world conditions. • No need to worry about entering physiologically impossible data by mistake. Data is checked for plausibility and for internal consistency using the Henderson-Hasselbalch equation. • An accurate analysis depends on an accurate anion gap. ABG Expert has you covered with automatic correction of the anion gap when albumin is provided. • Never again wonder about how a result was obtained. Detailed explanations include easy-to-understand equations so you can be sure the calculations are correct. Flexibility- • Need the arterial blood gas analysis, but not the anion gap or A-a gradient? No problem. ABG Expert can analyze the data for all three results separately or together. • Set the normal anion gap range based on the normal range at your institution. Or, use your patient’s own baseline anion gap to maximize your sensitivity to detect disorders. • Caring for an 80-year-old patient in Denver? Provide age and barometric pressure, and ABG Expert automatically adjusts interpretation of the A-a gradient. • Need more specificity? Adjust the normal delta gap range based on the literature you follow in your practice. • ABG Expert works as well in Bangkok as it does in Boston with full support for SI and non-SI units. Power- • Color-coded results allow for rapid analysis in critical situations. One additional click gives you a detailed differential diagnosis and additional recommendations. • Concerned about a new problem in your patient with advanced COPD? ABG Expert can adjust its calculations for chronic respiratory conditions so you can detect additional disorders that are missed by other apps. • Detailed explanations of disorders integrate ABG, anion gap, and A-a gradient results providing individualized answers like no textbook can. • Refine your differential diagnosis even further with the included osmolal gap and urine anion gap calculators. • ABG Expert combines beauty and brains with optimization for iOS devices running iOS 13 and later. Disclaimer: Brian Dale Vander Werf MD Inc. has made every effort to ensure the accuracy of the information included in this product. However, the authors, developers, and Brian Dale Vander Werf MD Inc. are not responsible for errors or omissions or for any consequences from the use of this product and make no warranty, expressed or implied, with respect to the currency, completeness, or accuracy of the contents of this product. This product has been designed as a supplemental source of information for medical professionals. This product is not a substitute for clinical judgment, and the use of the information produced by this product in a particular situation remains the responsibility of the medical professional. Privacy Policy: This product does not collect, store, or transmit individually identifiable health information. References: NEJM. 2014; 371: 1434. Medicine. 1980; 59(3): 161. Kidney International. 2009; 76: 1239. Emerg Med. 1990; 19: 1310. Clin J Am Soc Nephrol. 2007; 2: 162. Nat Rev Nephrol. 2010; 6: 274. Anaesthesia. 2008; 63: 294. Clin J Am Soc Nephrol. 2012; 7: 671. The ICU Book. 3rd ed. Lippincott Williams & Wilkins; 2007.

About

ABGs NOW!

Master arterial blood gas interpretation with this interactive tool. It offers a calculator for quick answers, practice sessions with hints, and a challenge mode to test your skills. Detailed analysis is provided for any errors, making learning engaging.

Highlights
  • ABG Calculator
  • Practice Mode with Hints
  • Challenge Mode
  • Detailed Analysis
  • Knowledge Strengthening
Features
Currently charting
Read full description

ABGs NOW!™ is a fun, engaging way for both students and professionals to strengthen their knowledge of arterial blood gases. The app features a calculator, providing immediate answers, a practice mode that guides the learner with helpful hints, and a challenge mode where learners can put their ABG skills to the test. Both practice and challenge modes provide detailed analysis for any missed interpretations. ​ ABGs NOW!™ offers an entertaining way to learn a challenging topic.

Screenshots

ABG Expert4 screens
ABGs NOW!4 screens

Verdict

The call

The clearest difference is price: ABG Expert at Free against ABGs NOW!'s $0.99. ABG Expert also leads on ratings volume (9 vs 2). ABGs NOW!'s advantage is update cadence (every 2 months vs every 5 months) and rating (5.0 vs 4.8). On ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

ABG Expert is free to download; ABGs NOW! costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

ABGs NOW! holds the better App Store score, 5.0 against 4.8. Both are backed by a comparable volume of ratings — 9 and 2 respectively.

UpkeepUpdate frequency

ABG Expert ships an update every 5 months, ABGs NOW! every 2 months. The most recent releases landed on June 9, 2026 and September 5, 2026 respectively.

Scorecard7 real differences · 4 level
ABG Expert versus ABGs NOW!: the parameters behind the verdict, then further details
ParameterABG ExpertABGs NOW!
PriceFree — better$0.99
Rating4.8 (9 ratings)5.0 (2 ratings) — better
Positive reviews100.0% of reviews—
Number of ratings9 — better2
Update frequencyEvery 5 monthsEvery 2 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
Best chart rank—#194 — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.010.0 — better
Further details — not scored
Size2 MB161 MB
Age rating12+12+
DeveloperBrian Dale Vander Werf MD IncBytewise Studios, LLC

Customer experience

ABG Expert

All ratings9 ratings
Positive88.9%
Neutral11.1%
Negative0.0%
Written reviews3 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

ABGs NOW!

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

ABG Expert

No in-app purchases

None

ABGs NOW!

No in-app purchases

Questions

Is ABG Expert free?
ABG Expert is free to download, with no in-app purchases.
Is ABGs NOW! free?
ABGs NOW! costs $0.99, with no in-app purchases.
Which has better reviews, ABG Expert or ABGs NOW!?
ABGs NOW! is rated higher. ABG Expert averages 4.8 out of 5 from 9 ratings, while ABGs NOW! averages 5.0 from 2 ratings.
Do ABG Expert or ABGs NOW! have ads?
Neither ABG Expert nor ABGs NOW! shows ads.
Which is updated more often, ABG Expert or ABGs NOW!?
ABG Expert ships an update every 5 months, and ABGs NOW! every 2 months. Most recently, ABG Expert was updated on June 9, 2026 and ABGs NOW! on September 5, 2026.

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