Apple usually warns users when an iOS application interacts with an external source.
In this case, the information is being shared between the Reacts secure, proprietary centralized login server and the Reacts iOS application. The information shared between our two system is a token that tells the iOS app that you are who you say you are and if you are allowed to access the app. The information about you is only being shared between Reacts iOS and Reacts identity server. This notification simply appears because our secure proprietary centralized login server is external to the iOS application.