# Sentry Technology vs Reef Trak

The clearest difference is in-app purchases: Sentry Technology at none against Reef Trak's 2. Sentry Technology also leads on iOS requirement (11.0 vs 17.0). Reef Trak's advantage is update cadence (weekly vs every 2 months). On price, ads and device support there is nothing between them.

Both are free to download. Reef Trak sells 2 in-app purchases, starting at $3.99 per month. Sentry Technology asks for nothing beyond the download.

Sentry Technology ships an update every 2 months, Reef Trak weekly. The most recent releases landed on October 8, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | Sentry Technology | Reef Trak |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.8 (43 ratings)](https://appshunter.io/ios/app/reef-trak-reef-manager/id6741099733/reviews)** |
| Number of ratings | — | **43** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Weekly** |
| Monetization | — | Freemium |
| Size | 38 MB | 120 MB |
| Requires iOS | **11.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Sentry Technology Pty Ltd](https://appshunter.io/developer/1646545662) | [Reef Research Labs LLC](https://appshunter.io/developer/1793070192) |

## What reviewers say

### Sentry Technology

[App page](https://appshunter.io/ios/app/sentry-technology/id6443494177)

**Features:** macOS Compatibility

**In-app purchases:** none


### Reef Trak

[App page](https://appshunter.io/ios/app/reef-trak-reef-manager/id6741099733)

This app helps reef tank enthusiasts manage all aspects of their aquarium, from daily testing and livestock records to equipment tracking and maintenance schedules. It provides tools for data analysis, trend spotting, and preventing costly mistakes, offering both free and premium features.

**Highlights:** Parameter logging and trend charts, Livestock library with care profiles, Tank health snapshots and data export, Equipment and maintenance tracking, Dosing calculators and unit converters, Progress photo logging

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Reef Trak Premium Monthly | $3.99 | per month |
| Reef Trak Lifetime | $9.99 | one-time |


## Frequently asked questions

### Is Sentry Technology free?

Sentry Technology is free to download, with no in-app purchases.

### Is Reef Trak free?

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

### Do Sentry Technology or Reef Trak have ads?

Neither Sentry Technology nor Reef Trak shows ads.

### Which is updated more often, Sentry Technology or Reef Trak?

Sentry Technology ships an update every 2 months, and Reef Trak weekly. Most recently, Sentry Technology was updated on October 8, 2026 and Reef Trak on October 15, 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.*