Comparison

12 Lead ECG Challenge vs arrhythmia

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

Head to head
About

12 Lead ECG Challenge

Master 12-lead ECG interpretation with real patient cases and expert explanations. This app helps EMS providers, nurses, and physicians build accuracy and confidence in identifying critical cardiac conditions through interactive learning and customized practice.

Highlights
  • Real patient 12-lead ECG cases
  • Wide range of cardiac pathologies
  • Interactive ECG examination
  • Expert explanations and rationale
  • Customized practice sessions
  • Zoom and move functionality
Features
Read full description

Master 12-Lead ECG Interpretation with Confidence Sharpen your ECG interpretation skills with 12-Lead ECG Challenge—the ultimate tool for EMS providers, nurses, and physicians. Created by Tom Bouthillet, renowned ECG expert and blogger, this app delivers 180 real-world 12-lead ECGs to help you build accuracy, speed, and confidence in identifying critical cardiac conditions. Key Features: • Real patient cases with clinically obtained 12-leads alongside actual patient complaints. • Wide range of pathologies, including acute STEMI, STEMI mimics, electrolyte imbalances, and more. • Interactive learning with zoom and move functionality for easy ECG examination on phones, tablets, and computers. • Expert explanations with detailed rationale and superimposed highlights to break down key findings. • Customized practice with options to review 5, 10, or 20 cases at a time and exclude mastered ECGs for efficient study. Perfect for cath lab activation teams, EMS, emergency medicine, and cardiology professionals, this app ensures you're prepared for high-stakes, real-world decisions. Download now and take your ECG interpretation to the next level!

About

arrhythmia

Practice interpreting EKGs in lead II with realistic simulations. Choose rhythms to study or test your knowledge in a game mode. Ideal for healthcare professionals to hone their diagnostic skills.

Highlights
  • EKG interpretation practice
  • Lead II simulation
  • Study Mode with rhythm selection
  • Game Mode for random rhythm identification
  • Customizable rhythm sets
  • Realistic rhythm variations
Read full description

Practice reading EKGs in lead II Basic EKG interpretation is more accurately described as an intermediate level skill that takes time, practice and refreshing. Whether you are a doctor, nurse, EMT or tech your ability to read and pickup on basic EKG changes in real time is essential. Practice with an app that actually looks like what you see at work. Use the app’s ‘Study Mode’ to choose one or multiple rhythms to view and compare. A brief description of each rhythm is provided, you can also pause and restart rhythms. Delete and add specific rhythms as desired. Rates, amplitudes and widths of the rhythms are dynamically set which provides for a more realistic simulation and variation within each type of rhythm. Use the app’s ‘Game Mode’ to challenge yourself to identify rhythms presented randomly in lead II. If desired, you can also custom specify which rhythms to include in the game. Access to Study Mode and Game Mode requires a subscription via in-app purchase. Please Read: The purpose of this app is not to teach basic EKG interpretation but rather to practice basic EKG interpretation. If you don’t know basic EKG interpretation seek out additional resources such as classes, books, online materials and mentors to learn more and further your understanding. Note: The cardiac rhythms presented by the app are simulated approximations. There is NO guarantee to the accuracy of rhythms presented. While accuracy is not guaranteed it is a goal. Please report errors, suggestions or general feedback to: feedback@arrhythmiaApp.com. Arrhythmia uses the standard Apple Terms of Use End User License Agreement (EULA): http://www.apple.com/legal/itunes/appstore/dev/stdeula

Screenshots

12 Lead ECG Challenge4 screens
arrhythmia4 screens

Verdict

The call

The clearest difference is price: arrhythmia at Free against 12 Lead ECG Challenge's $5.99. arrhythmia also leads on rating (4.1 vs 3.3) and update cadence (every 3 weeks vs every 10 months). 12 Lead ECG Challenge's advantage is in-app purchases (none vs 3) and review sentiment (69% vs 44%). On ads, device support and iOS requirement 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

arrhythmia is free to download; 12 Lead ECG Challenge costs $5.99 up front. arrhythmia sells 3 in-app purchases, starting at $2.99 per month. 12 Lead ECG Challenge asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

arrhythmia holds the better App Store score, 4.1 against 3.3. That said, the two scores are not equally well evidenced: arrhythmia has 113 ratings behind it against 4, so its average is the more settled of the two. Written reviews complicate that: 69% of 12 Lead ECG Challenge's written reviews are positive against 44% of arrhythmia's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

12 Lead ECG Challenge ships an update every 10 months, arrhythmia every 3 weeks. The most recent releases landed on November 2, 2026 and November 1, 2026 respectively.

Scorecard7 real differences · 3 level
12 Lead ECG Challenge versus arrhythmia: the parameters behind the verdict, then further details
Parameter12 Lead ECG Challengearrhythmia
Price$5.99Free — better
Rating3.3 (4 ratings)4.1 (113 ratings) — better
Positive reviews68.8% of reviews — better43.9% of reviews
Number of ratings4113 — better
Update frequencyEvery 10 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaid — betterSubscription
DevicesiPhone, iPadiPhone, iPad, Mac — better
Requires iOS17.617.6
Further details — not scored
Size51 MB159 MB
Age rating17+17+
DeveloperLimmer CreativeSingle Sail Software, LLC

Customer experience

12 Lead ECG Challenge

All ratings4 ratings
Positive50.0%
Neutral0.0%
Negative50.0%
Written reviews16 reviews
Positive68.8%
Neutral12.5%
Negative18.8%

arrhythmia

All ratings111 ratings
Positive80.2%
Neutral4.5%
Negative15.3%
Written reviews41 reviews
Positive43.9%
Neutral7.3%
Negative48.8%

Bugs and requests

12 Lead ECG Challenge

Not enough reviews yet to summarise bugs or requests.

arrhythmia

Reported bugs

2 issues
  • App no longer works after iOS update
  • App does not work on Apple Watch

Requested features

11 requests
  • Add more common and important rhythms (torsades, WPW, STEMI, accelerated/tachycardic idioventricular, WAP, MAT)
  • Option to read as a 12-lead instead of a single rhythm line
  • Add variations to rhythms
  • Add Left Bundle Branch Block
  • Add a 12-lead option
Show 6 more
  • Add more examples for each rhythm
  • Add a list view option for rhythms
  • Add an explanation/rationale for correct/incorrect answers
  • Add an animation showing what is happening in the heart when an answer is wrong
  • Add tutorial or information on how to use the app
  • Add 'Non-Conducted' PACs and similar rhythms

In-app purchases

None

12 Lead ECG Challenge

No in-app purchases

3 purchases

arrhythmia

Subscriptions2
  • Monthly7 Days trial$2.991 Month
  • Yearly7 Days trial$19.991 Year
One-time1
  • Unlock All Rhythms (One-time Purchase)$4.99

Questions

Is 12 Lead ECG Challenge free?
12 Lead ECG Challenge costs $5.99, with no in-app purchases.
Is arrhythmia free?
arrhythmia is free to download, with in-app purchases available.
Which has better reviews, 12 Lead ECG Challenge or arrhythmia?
arrhythmia is rated higher. 12 Lead ECG Challenge averages 3.3 out of 5 from 4 ratings, while arrhythmia averages 4.1 from 113 ratings.
Do 12 Lead ECG Challenge or arrhythmia have ads?
Neither 12 Lead ECG Challenge nor arrhythmia shows ads.
Which is updated more often, 12 Lead ECG Challenge or arrhythmia?
12 Lead ECG Challenge ships an update every 10 months, and arrhythmia every 3 weeks. Most recently, 12 Lead ECG Challenge was updated on November 2, 2026 and arrhythmia on November 1, 2026.

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