# Stress Duck vs Protocol AI

The clearest difference is in-app purchases: Stress Duck at none against Protocol AI's 8. Stress Duck also leads on update cadence (every 2 days vs every 4 days). Protocol AI's advantage is iOS requirement (15.1 vs 17.0). On price, review sentiment, ads and device support there is nothing between them.

Both are free to download. Protocol AI sells 8 in-app purchases, starting at $4.99 per month. Stress Duck asks for nothing beyond the download.

Stress Duck ships an update every 2 days, Protocol AI every 4 days. The most recent releases landed on June 10, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | Stress Duck | Protocol AI |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[1.0 (1 ratings)](https://appshunter.io/ios/app/protocol-ai/id6742851434/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 0.0% of reviews | 0.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 days** | Every 4 days |
| Monetization | **Free** | Free with in-app purchases |
| Size | 27 MB | 52 MB |
| Requires iOS | 17.0 | **15.1** |
| Devices | **iPhone, iPad, Apple Watch** | iPhone, iPod |
| Age rating | 12+ | 4+ |
| Developer | [子龙 郭](https://appshunter.io/developer/1499776496) | [WARREN JAMES DAY](https://appshunter.io/developer/1800318577) |

## What reviewers say

### Stress Duck

[App page](https://appshunter.io/ios/app/stress-duck/id6472258375)

This app helps you manage daily stress and track your mood. It integrates with Apple Health to display health data like step count and sleep, offering a simple way to monitor your well-being and encourage happiness.

**Highlights:** Daily mood and stress status check, Apple Health data integration, View step count, sleep, and calorie info, Privacy-focused data handling, Encourages happiness and stress reduction

**Features:** macOS Compatibility

**In-app purchases:** none


### Protocol AI

[App page](https://appshunter.io/ios/app/protocol-ai/id6742851434)

This app acts as a personal training partner, offering intelligent recovery tracking and personalized workout plans. It helps users train smarter, recover effectively, and achieve fitness goals faster by providing insights into body readiness and performance metrics.

**Highlights:** Intelligent recovery tracking, Personalized workout plans, Body Battery readiness indicator, Workout logging with rest timers, Performance and sleep insights

**Features:** macOS Compatibility

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlimited access | $4.99 | per month |
| Unlimited access | $4.99 | per month |
| Unlimited access | $14.99 | per month |
| Unlimited access | $14.99 | per month |
| Unlimited access | $39.99 | per year |
| Unlimited access | $39.99 | per year |
| Unlimited access | $39.99 | per year |
| Unlimited access | $59.99 | per year |


## Frequently asked questions

### Is Stress Duck free?

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

### Is Protocol AI free?

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

### Do Stress Duck or Protocol AI have ads?

Neither Stress Duck nor Protocol AI shows ads.

### Which is updated more often, Stress Duck or Protocol AI?

Stress Duck ships an update every 2 days, and Protocol AI every 4 days. Most recently, Stress Duck was updated on June 10, 2026 and Protocol AI on September 16, 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.*