AppSync Client in Android Service

U cannot find a proper use case in the docs and examples. I need the app to be as up to date with server data as possible that is why I am aiming to use Delta Sync. Where put the call to sync method ? Should it be placed inside an activity ? But in case of switching an activity I am going to lose the client.
Is it a good idea to our it in a service (have not decided if this would be foreground or background service) ? The idea is to integrate callbacks from AppSync with rxjava and subscribe to them.

Are there any possible problems when using AppSync API + DropIn auth + AWSMibule client in a service ?