ApolloOne is for a very different audience than Nitro. In my experience, ApolloOne is a very fast and effective viewer with decent file management and (more recently) a very basic quick edit functionality. My wife uses it solely to view my images in a shared folder on our shared Mac. It does not compare well with Nitro largely because it does not play on the same field so to speak, with none of the advanced raw editing functionality and no interface with Apple Photos. If someone already has Nitro (or Raw Power), I see little value in having ApolloOne as well but for what it does do, it does well.
