# SleepDev vs Isochron

The clearest difference is in-app purchases: SleepDev at none against Isochron's 1. SleepDev also leads on iOS requirement (12.0 vs 17.6). On price, ads and device support there is nothing between them.

Both are free to download. Isochron sells 1 one-off in-app purchase. SleepDev asks for nothing beyond the download.

## The numbers

| Metric | SleepDev | Isochron |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | — | Every 6 weeks |
| Size | 25 MB | 4 MB |
| Requires iOS | **12.0** | 17.6 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 17+ |
| Developer | [高铭 张](https://appshunter.io/developer/1846527898) | [Seth Adam Mundall](https://appshunter.io/developer/1626079549) |

## What reviewers say

### SleepDev

[App page](https://appshunter.io/ios/app/sleepdev/id6754155833)

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

**In-app purchases:** none


### Isochron

[App page](https://appshunter.io/ios/app/isochron-watch-accuracy/id6780989450)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Isochron Pro | $9.99 | one-time |


## Frequently asked questions

### Is SleepDev free?

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

### Is Isochron free?

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

### Do SleepDev or Isochron have ads?

Neither SleepDev nor Isochron shows ads.

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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.*