# Mersindex vs Sleep Sync

The clearest difference is update cadence: Sleep Sync at fortnightly against Mersindex's monthly. Mersindex's advantage is iOS requirement (13.0 vs 15.1). 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.

Mersindex ships an update monthly, Sleep Sync fortnightly. The most recent releases landed on October 9, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | Mersindex | Sleep Sync |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Monthly | **Fortnightly** |
| Size | 27 MB | 13 MB |
| Requires iOS | **13.0** | 15.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 17+ | 4+ |
| Developer | [Yasin Kucuk](https://appshunter.io/developer/1768059846) | [KASEM SAMRA](https://appshunter.io/developer/6811391200) |

## What reviewers say

### Mersindex

[App page](https://appshunter.io/ios/app/mersindex/id6677047098)

**Features:** macOS Compatibility

**In-app purchases:** none


### Sleep Sync

[App page](https://appshunter.io/ios/app/sleep-sync-sleep-tracker/id6811392546)

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

**In-app purchases:** none


## Frequently asked questions

### Is Mersindex free?

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

### Is Sleep Sync free?

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

### Do Mersindex or Sleep Sync have ads?

Neither Mersindex nor Sleep Sync shows ads.

### Which is updated more often, Mersindex or Sleep Sync?

Mersindex ships an update monthly, and Sleep Sync fortnightly. Most recently, Mersindex was updated on October 9, 2026 and Sleep Sync on October 4, 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.*