# arrhythmia vs Certa Dose

The clearest difference is review sentiment: Certa Dose at 100% against arrhythmia's 44%. Certa Dose also leads on rating (5.0 vs 4.2) and iOS requirement (13.0 vs 17.6). arrhythmia's advantage is update cadence (every 3 weeks vs every 3 months) and ratings volume (111 vs 5). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. arrhythmia sells 3 in-app purchases, starting at $2.99 per month and Certa Dose sells 2 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

Certa Dose holds the better App Store score, 5.0 against 4.2. That said, the two scores are not equally well evidenced: arrhythmia has 111 ratings behind it against 5, so its average is the more settled of the two. Written reviews point the same way: 44% of arrhythmia's written reviews are positive against 100% of Certa Dose's.

arrhythmia ships an update every 3 weeks, Certa Dose every 3 months. The most recent releases landed on October 13, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | arrhythmia | Certa Dose |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.2 (111 ratings)](https://appshunter.io/ios/app/arrhythmia/id996560473/reviews) | **[5.0 (5 ratings)](https://appshunter.io/ios/app/certa-dose/id1524942244/reviews)** |
| Number of ratings | **111** | 5 |
| Positive reviews | 43.9% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 3 months |
| Monetization | Subscription | Subscription |
| Size | 159 MB | 16 MB |
| Requires iOS | 17.6 | **13.0** |
| Devices | **iPhone, iPad, Mac** | iPhone, iPod |
| Age rating | 17+ | 17+ |
| Developer | [Single Sail Software, LLC](https://appshunter.io/developer/359715495) | [Certa Dose, Inc.](https://appshunter.io/developer/1524942636) |

## What reviewers say

### arrhythmia

[App page](https://appshunter.io/ios/app/arrhythmia/id996560473)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $2.99 | per month |
| Yearly | $19.99 | per year |
| Unlock All Rhythms (One-time Purchase) | $4.99 | one-time |


### Certa Dose

[App page](https://appshunter.io/ios/app/certa-dose/id1524942244)

This app helps healthcare professionals confidently administer high-risk medications. It provides visual verification for each step, estimates weight-based doses, and documents sessions instantly. Designed to reduce critical dosing errors, it offers peace of mind in high-stress medical environments.

**Highlights:** Visual medication administration verification, Weight-based dose estimation, Syringe volume visualization, Instant session documentation, Medication information and contraindications, Virtual pediatric measuring tape

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly plan | $3.99 | per month |
| Yearly subscription | $29.99 | per year |


## Frequently asked questions

### Is arrhythmia free?

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

### Is Certa Dose free?

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

### Which has better reviews, arrhythmia or Certa Dose?

Certa Dose is rated higher. arrhythmia averages 4.2 out of 5 from 111 ratings, while Certa Dose averages 5.0 from 5 ratings.

### Do arrhythmia or Certa Dose have ads?

Neither arrhythmia nor Certa Dose shows ads.

### Which is updated more often, arrhythmia or Certa Dose?

arrhythmia ships an update every 3 weeks, and Certa Dose every 3 months. Most recently, arrhythmia was updated on October 13, 2026 and Certa Dose on October 10, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*