I would like to check if my user has a Google or an Amazon device
This will help me to redirect to the right review page within the App
Is there anyway to do that?
It seems like this heavily depends on the package name. Ones that uses the Google play store start with com.android and Amazon's store is com.amazon.
Check out the code here in this post to see how you can implement this:
Xamarin Inc., as a wholly-owned Microsoft subsidiary acting as a separate legal entity, adheres to the Microsoft Privacy Statement: Privacy & cookies