Skippy says you have to authorize through the stand alone version. I am running OSX Mojave and UNIFY is running fine. It was just launched on Monday. He isn’t releasing a demo version until after the introductory period has expired (February). He’s been demoing it in his videos while he’s been developing it. Watch the video…
Why use it? I believe there are many advantages. First, it has 8 plugin instruments built in and comes with more than 400 of Skippy’s patches - worth the cost by itself IMHO. Plus built in MIDI FX and Audio FX. It’s extremely efficient on CPU usage and you can stack layers of sounds with your own instruments and effects and save them as presets. Insert FX or Send FX. And/or save/Import layers. There’s also many ways to use it. And the patches load extremely fast without predictive loading.
I personally like the workflow. You can create very complex patches quickly. The macros are quick to use and very powerful and he claims that they can access a depth of plugin parameters that are inaccessible on other platforms. It looks like it will save me many hours of programming.
I have been able to open and use it (on a basic level within GigPerformer), but I have not had time to dive deeply yet.