# Protocol Zero vs StrengthLens

The clearest difference is in-app purchases: StrengthLens at none against Protocol Zero's 5. StrengthLens also leads on ads (none vs shown) and rating (5.0 vs 4.7). Protocol Zero's advantage is ratings volume (182 vs 2). On price and update cadence there is nothing between them.

Both are free to download. Protocol Zero sells 5 in-app purchases, starting at $12.99 per month. StrengthLens asks for nothing beyond the download.

StrengthLens holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Protocol Zero has 182 ratings behind it against 2, so its average is the more settled of the two.

Protocol Zero ships an update every 4 days, StrengthLens weekly. The most recent releases landed on October 1, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | Protocol Zero | StrengthLens |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (182 ratings)](https://appshunter.io/ios/app/protocol-zero-sleep-sounds/id6755014746/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/strengthlens/id6757731105/reviews)** |
| Number of ratings | **182** | 2 |
| Positive reviews | 66.7% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 4 days** | Weekly |
| Monetization | Subscription | **Free** |
| Size | 123 MB | 44 MB |
| Requires iOS | 17.2 | **15.1** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 12+ | 4+ |
| Developer | [HumanOS LLC](https://appshunter.io/developer/1851339721) | [Kushal Singh](https://appshunter.io/developer/1866416378) |

## What reviewers say

### Protocol Zero

[App page](https://appshunter.io/ios/app/protocol-zero-sleep-sounds/id6755014746)

This app provides a personalized daily plan to improve sleep quality, incorporating science-backed techniques and sleep sounds. It guides users through setting consistent wake times, managing caffeine intake, and activating wind-down routines for better rest.

**Highlights:** Personalized daily sleep plan, Sleep sounds (white noise, rain), Consistent wake time guidance, Caffeine cutoff reminders, Wind-down mode, CBT-I techniques

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Protocol Zero Monthly | $12.99 | per month |
| Protocol Zero Annual Starter | $19.99 | per year |
| Protocol Zero Annual | $29.99 | per year |
| Protocol Zero Pro | $39.99 | per year |
| Protocol Zero Pro | $59.99 | per year |


### StrengthLens

[App page](https://appshunter.io/ios/app/strengthlens/id6757731105)

This app helps you track your strength training progress with science-based principles. It offers smart workout logging, custom program building, and advanced analytics to help you train smarter and get stronger.

**Highlights:** Smart workout tracking (sets, reps, weight, RPE), Custom workout program builder, Advanced progress analytics, AI-powered recommendations, Offline functionality, Science-based training principles

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Protocol Zero free?

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

### Is StrengthLens free?

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

### Which has better reviews, Protocol Zero or StrengthLens?

StrengthLens is rated higher. Protocol Zero averages 4.7 out of 5 from 182 ratings, while StrengthLens averages 5.0 from 2 ratings.

### Do Protocol Zero or StrengthLens have ads?

Protocol Zero shows ads; StrengthLens does not.

### Which is updated more often, Protocol Zero or StrengthLens?

Protocol Zero ships an update every 4 days, and StrengthLens weekly. Most recently, Protocol Zero was updated on October 1, 2026 and StrengthLens on October 6, 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.*