What's the purpose of Revenuecat?

Hi,

I'm developing a game and I'm starting to ponder the monetization topic.
During my researches, I stumbled into this service (https://docs.revenuecat.com/docs/unity) and I don't understand which is its purpose, Unity has its own IAP Service.

Why does something like revenuecat exist then? (I mean for unity, I understand its existence for other platforms).
Which problems is it trying to solve?

Thanks for helping me to clarify that.

 

It looks be a helper/wrapper for Unity IAP https://docs.revenuecat.com/docs/welcome

 

I'm still learning this myself... but from my understanding.... I think maybe Revenuecat will let people subscribe once, and then install/play on windows/ios/android without having to pay additional subscriptions. Maybe with Unity IAP, people would have to subscribe for each platform or purchase separate DLC for each platform separately?

Can an expert let me know if this theory is right or wrong?

 

We use RevenueCat with one of our apps,
mainly we use it as a Backend service to maintain subscription details.

For example as @lclemens said, you can use it so once a user subscribed through iOS, they still can access the app through their Android devices ( using some sort of Authentication service, in our case we use PlayFab )

Also using RevenueCat we are able to provide free subscriptions as gifts for some users, something like iTunes promo codes, but without it's limitations.

I think it include other features too that we don't use,
for example if you have more than one iap-product/price using their SDK you can control what you show to the user like testing with prices without submitting new build.

if you have your own dedicated backend/web server to manage subscriptions, then you don't need to use it.