Third-party apps for writing Sleep Stage data to Health app?

Hello Tchitcherine,

Thanks for asking about third-party sources. While we can't begin to guess what apps do it, and then what apps you might have on your phone with that possibility, we might be able to give you one better option.

Go check your input sources! Manage Health data on your iPhone, iPod touch, or Apple Watch

"View your data sources

Here's how to see which devices and apps update specific health categories:

1. Open the Health app and tap the Browse tab. 
2. Tap a category, like Activity. If you don't see the category, swipe down to reveal the search bar, then enter a category.
3. Tap a subcategory, like Steps.
4. Scroll down, then tap Data Sources & Access. Only the sources that contribute to that data type will appear. 

Here's how to see all of your sources for the Health app:

1. Open the Health app. 
2. Tap your profile picture in the upper-right corner . 
3. Scroll down to Privacy, then tap Apps or Devices."

Once you know the apps feeding into your Health app, then all you need to do is check them in the App Store to see if that's the one with the sleep capabilities. Thanks.