They can also work in combination with Redux, as shown here (https://github.com/Hongbo-Miao/apollo-chat).
Managing State in Angular Applications
Victor Savkin
3K21

Unfortunately there’s no working integration of ngrx/store with the Apollo store at the time (see issue). The app from the repo you linked is actually maintaining two separate Redux stores, which isn’t necessarily the desired goal.

You can however integrate the Apollo store directly with an angular-redux store as I’ve explained in the docs.

Here’s a little example app that showcases a working integration of Redux and Apollo into one single store.