# Target Zone Keeper vs Aqua8tine

The clearest difference is update cadence: Aqua8tine at every 6 days against Target Zone Keeper's every 7 months. Aqua8tine also leads on iOS requirement (15.1 vs 17.6). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Target Zone Keeper ships an update every 7 months, Aqua8tine every 6 days. The most recent releases landed on October 9, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Target Zone Keeper | Aqua8tine |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/target-zone-keeper/id6673919937/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 6 days** |
| Monetization | Free | — |
| Size | 2 MB | 29 MB |
| Requires iOS | 17.6 | **15.1** |
| Devices | iPhone, Apple Watch | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Margarita Bliznikova](https://appshunter.io/developer/1765769948) | [Khalil Missaoui](https://appshunter.io/developer/1822610639) |

## What reviewers say

### Target Zone Keeper

[App page](https://appshunter.io/ios/app/target-zone-keeper/id6673919937)

This app helps improve cardiovascular fitness by guiding users to maintain their heart rate within an optimal zone for VO2 max enhancement. It offers non-disruptive alerts and visual cues, requiring minimal wrist interaction for seamless workout integration.

**Highlights:** Maintains target heart rate zone, Minimal wrist interaction required, Simple, intuitive setup, Customizable, non-disruptive alerts, Personalized heart rate zones, Apple Health integration

**In-app purchases:** none


### Aqua8tine

[App page](https://appshunter.io/ios/app/aqua8tine/id6748324129)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Target Zone Keeper free?

Target Zone Keeper is free to download, with no in-app purchases.

### Is Aqua8tine free?

Aqua8tine is free to download, with no in-app purchases.

### Do Target Zone Keeper or Aqua8tine have ads?

Neither Target Zone Keeper nor Aqua8tine shows ads.

### Which is updated more often, Target Zone Keeper or Aqua8tine?

Target Zone Keeper ships an update every 7 months, and Aqua8tine every 6 days. Most recently, Target Zone Keeper was updated on October 9, 2026 and Aqua8tine on October 28, 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.*