ApolloCombine is a collection of Combine publishers for the Apollo iOS client. The collection is available via Swift Package Manager and CocoaPods on GitHub. The repo contains usage instructions.
In late 2019, I made the decision to use the Combine framework in one of our production apps. I started by incrementally replacing some of the flow-control code in the UI, then began to look for other places to use Combine. The one place I really wanted to attack was the network layer, which uses the Apollo iOS client to (ultimately) communicate with our REST API. This package is the result of that work.
Of the five main operations in the Apollo client, I currently use three extensively in production: fetch, perform, and upload. The other two operations (watch and subscribe) have been tested, but have not received the same attention.