On top of that you are also able to manually add single games even if they are not connected to any platform. By connecting platforms, the data about the games you own is automatically imported to the application. In GOG GALAXY 2.0 you’re adding games through official and community created integrations.
And the application is entirely free, all you need is a GOG account to use it.
If your games and gaming buddies are scattered between different launchers and platforms, this is a solution for you! Keeping track of all achievements earned by you and your friends, hours played, and games owned across platforms has never been this easy. GOG GALAXY 2.0 is an application, thanks to which you’ll be able to combine multiple libraries into one and connect with your friends across all gaming platforms, consoles included. What is GOG GALAXY 2.0 and why should I use it?.