# Reefability vs Entropy Alarm

The clearest difference is price: Reefability at Free against Entropy Alarm's $2.99. Reefability also leads on ratings volume (36 vs 1) and update cadence (daily vs every 5 days). Entropy Alarm's advantage is rating (5.0 vs 3.1) and in-app purchases (none vs 9). On ads and device support there is nothing between them.

Reefability is free to download; Entropy Alarm costs $2.99 up front. Reefability sells 9 in-app purchases, starting at $9.99 per month. Entropy Alarm asks for nothing beyond the download.

Entropy Alarm holds the better App Store score, 5.0 against 3.1. That said, the two scores are not equally well evidenced: Reefability has 36 ratings behind it against 1, so its average is the more settled of the two.

Reefability ships an update daily, Entropy Alarm every 5 days. The most recent releases landed on October 20, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | Reefability | Entropy Alarm |
| --- | --- | --- |
| Price | **Free** | $2.99 |
| Rating | [3.1 (36 ratings)](https://appshunter.io/ios/app/reefability/id6636472070/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/entropy-alarm/id6808736350/reviews)** |
| Number of ratings | **36** | 1 |
| Positive reviews | 38.2% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Daily** | Every 5 days |
| Monetization | **Free with in-app purchases** | Paid |
| Size | 81 MB | 9 MB |
| Requires iOS | **15.0.0** | 26.1 |
| Devices | **iPhone, iPad, iPod, Apple Watch** | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Reefability](https://appshunter.io/developer/1762764786) | [Mark Garcia](https://appshunter.io/developer/1772481137) |

## What reviewers say

### Reefability

[App page](https://appshunter.io/ios/app/reefability/id6636472070)

This AI-powered app offers scientific precision for managing coral reef aquariums. It analyzes microbiome health, water chemistry, and light optimization, and can identify issues from tank photos. It provides tools for hobbyists and professionals to maintain thriving reef ecosystems.

**Highlights:** AI-driven analysis of reef tank health, Smart photo diagnostics for issue identification, Evidence-based solutions and recommendations, Ecosystem stability insights, Professional tools for reef stores and professionals, Integrated parameter monitoring

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (9)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1-Month | $9.99 | per month |
| Controller plan (monthly) | $11.99 | per month |
| 12-Month | $34.99 | per year |
| Controller plan (annual) | $49.99 | per year |
| Day pass | $1.99 | one-time |
| 5 tank rebuilds | $2.99 | one-time |
| Week pass | $4.99 | one-time |
| 15 tank rebuilds | $6.99 | one-time |
| Month pass | $12.99 | one-time |


### Entropy Alarm

[App page](https://appshunter.io/ios/app/entropy-alarm/id6808736350)

This alarm app automatically manages your alarms, clearing them when no longer needed. It offers three distinct alarm types to keep your list organized and includes features for travel, holidays, and custom sounds. Live Activities and widgets provide at-a-glance information.

**Highlights:** Self-clearing alarms, Burner, Frozen, and Crystallized alarm types, Follow me and Stay put travel modes, Holiday and custom day off skipping, Live Activities and Home Screen widget, Siri and Shortcuts integration

**Features:** Apple Watch app, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Reefability free?

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

### Is Entropy Alarm free?

Entropy Alarm costs $2.99, with no in-app purchases.

### Which has better reviews, Reefability or Entropy Alarm?

Entropy Alarm is rated higher. Reefability averages 3.1 out of 5 from 36 ratings, while Entropy Alarm averages 5.0 from 1 ratings.

### Do Reefability or Entropy Alarm have ads?

Neither Reefability nor Entropy Alarm shows ads.

### Which is updated more often, Reefability or Entropy Alarm?

Reefability ships an update daily, and Entropy Alarm every 5 days. Most recently, Reefability was updated on October 20, 2026 and Entropy Alarm on October 9, 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.*