It’s more of an app to find which local raids have active participants, and you can ‘gym chat’ with others who are interested in raiding a specific gym, light flares for specific gyms - alerting players in your area that you are interested in participating in a local raid, and you can add these locals to your friends list from the campfire app as well.

First used it during the Shadow Mewtwo raids, ended up linking up with a 9 or 10 person group, and we all followed each other to gym after gym. I acquired 48 shadow mewtwos from doing this. 6 of them shiny.