# System Zero vs Gratlock

The clearest difference is ads: Gratlock at none against System Zero's shown. System Zero's advantage is device support (3 vs 1) and iOS requirement (15.0 vs 17.0). On price, update cadence and in-app purchases there is nothing between them.

Both are free to download. System Zero sells 3 in-app purchases, starting at $12.99 per month and Gratlock sells 3 in-app purchases, starting at $7.00 per 7 days. Whichever you choose, the download price is not the number that matters.

Both ship on a similar rhythm, roughly weekly. The most recent releases landed on October 18, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | System Zero | Gratlock |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/gratlock-gratitude-journal/id6793295411/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Weekly | Weekly |
| Monetization | — | Subscription |
| Size | 65 MB | 11 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 12+ |
| Developer | [Abdelrahman Mohammed](https://appshunter.io/developer/1679252760) | [QRACKED LLC](https://appshunter.io/developer/1656898966) |

## What reviewers say

### System Zero

[App page](https://appshunter.io/ios/app/system-zero-self-improvement/id6778561681)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| System Zero Pro - Monthly | $12.99 | per month |
| System Zero Pro - Yearly | $59.99 | per year |
| System Zero Pro - Yearly | $59.99 | per year |


### Gratlock

[App page](https://appshunter.io/ios/app/gratlock-gratitude-journal/id6793295411)

This app transforms your existing app usage into a gratitude practice. Before opening selected apps, you're prompted to write one sentence about what you're grateful for. Your entries are saved in a private journal, and your apps unlock for a chosen duration.

**Highlights:** App usage as gratitude prompt, One-sentence journal entries, Private on-device journal, Customizable app blocking, Timed app unlock windows, Plain-text journal export

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Weekly | $7.00 | per 7 days |
| Pro Yearly Offer | $24.99 | per year |
| Pro Yearly | $49.99 | per year |


## Frequently asked questions

### Is System Zero free?

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

### Is Gratlock free?

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

### Do System Zero or Gratlock have ads?

System Zero shows ads; Gratlock does not.

### Which is updated more often, System Zero or Gratlock?

System Zero ships an update weekly, and Gratlock weekly. Most recently, System Zero was updated on October 18, 2026 and Gratlock on October 25, 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.*