arrhythmia vs CardioLens
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- EKG interpretation practice
- Lead II simulation
- Study Mode with rhythm selection
- Game Mode for random rhythm identification
- Customizable rhythm sets
- Realistic rhythm variations
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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
CardioLens
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CardioLens is the AI-powered ECG EKG analysis and learning platform built for medical students, nurses, paramedics, and physicians to master cardiac rhythm interpretation in seconds. AI-POWERED ECG ANALYSIS Upload any ECG strip — live camera or photo library — and get instant AI interpretation including rhythm identification, rate calculation, interval measurements, and clinical teaching points. Powered by Anthropic's Claude AI. LEARN & MASTER 40+ RHYTHMS Study Normal, Atrial, Junctional, Ventricular, and Bradycardic rhythms with interactive waveforms and detailed clinical explanations. Quiz yourself with 288 questions across 36 rhythms, and test real-world knowledge with 60 clinical cases across 10 series. Live rhythm strips run on true ECG paper (25 mm/s, 10 mm/mV), and the caliper reads real milliseconds and millivolts. ACLS ALGORITHMS & MEGA CODES Quick reference for Cardiac Arrest, Tachycardia, and Bradycardia protocols linked directly to ECG rhythms. Master 5 MEGA CODE simulations — consequence-driven decision trees that simulate real resuscitation scenarios. 13 DEEP-DIVE STUDY MODULES Interactive lessons covering PQRST Waves, Conduction System, Coronary Vessels, Bundle Branch Blocks, Heart Rate Calculation, ECG Paper, Axis Interpretation, Electrolytes, ST Segment Deep Dive, QTc Calculation, VT vs SVT (Brugada), Sgarbossa Criteria, and Pacemaker Basics. BUILT FOR IPHONE DUO Open your iPhone Duo and CardioLens fills the inner screen, held like a book or upright. Closed, the cover works just like your iPhone. SUBSCRIPTION PLANS - Free: 3 scans/month, Normal/Atrial/Junctional ECGs, 4 study modules - Monthly: 50 scans/month + full content access - Annual: Best value — 3-day free trial, 50 scans/month, cancel anytime TOP-UP CREDIT PACKS Need more scans? Purchase credits anytime: - 10 Credits - 30 Credits - 75 Credits Credits never expire and work with any subscription tier. Disclaimer: CardioLens is designed exclusively for educational purposes. It is NOT a clinical diagnostic tool and should not be used for patient care decisions. Terms of Use: https://www.cardiolens.ca/terms Privacy Policy: https://www.cardiolens.ca/privacy
Screenshots
Verdict
The clearest difference is update cadence: CardioLens at every 6 days against arrhythmia's every 3 weeks. arrhythmia's advantage is chart position (#160 vs unranked) and device support (3 vs 1). On price, ads, in-app purchases 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
Both are free to download. arrhythmia sells 3 in-app purchases, starting at $2.99 per month and CardioLens sells 5 in-app purchases, starting at $7.99 per month. Whichever you choose, the download price is not the number that matters.
arrhythmia ships an update every 3 weeks, CardioLens every 6 days. The most recent releases landed on October 26, 2026 and October 25, 2026 respectively.
| Parameter | arrhythmia | CardioLens |
|---|---|---|
| Price | Free | Free |
| Rating | 4.1 (113 ratings) — better | — |
| Positive reviews | 43.9% of reviews | — |
| Number of ratings | 113 — better | — |
| Update frequency | Every 3 weeks | Every 6 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Subscription | — |
| Best chart rank | #160 — better | — |
| Devices | iPhone, iPad, Mac — better | iPhone |
| Requires iOS | 17.6 | 17.6 |
| Further details — not scored | ||
| Size | 159 MB | 8 MB |
| Age rating | 17+ | 4+ |
| Developer | Single Sail Software, LLC | Mark Daniel Figueroa |
Bugs and 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
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- 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
CardioLens
Not enough reviews yet to summarise bugs or requests.
In-app purchases
arrhythmia
- Monthly7 Days trial$2.991 Month
- Yearly7 Days trial$19.991 Year
- Unlock All Rhythms (One-time Purchase)$4.99
CardioLens
- CardioLens Pro — Monthly$7.991 Month
- CardioLens Pro - Annual3 Days trial$59.991 Year
- 10 Scan Credits$2.99
- 30 Scan Credits$5.99
- 75 Scan Credits$9.99
Questions
Is arrhythmia free?
Is CardioLens free?
Do arrhythmia or CardioLens have ads?
Which is updated more often, arrhythmia or CardioLens?
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