Read this linked thread very thoroughly, a couple times if needed until you understand what to do. There are two versions of this app, so please read through understand which you need. It isn't hard to do this, but there are very particular steps to follow.
Far as installing apps/drivers, it is very easy, it is basically pointing the hub to a Github folder, and it imports the code for you. You then just save what it imports. https://docs.hubitat.com/index.php?title=Drivers_Code
