Thanks to both Darryl and Alyona,
The confusion was that you can install one licence on up to 5 desktop/laptops. It doesn't include a phone because Android or iPhone are in themselves standalone products. So I can understand the 24.95 extra price for Android.
I will have to buy both and hope wifi-sync works. What I need is not the whole standalone Android phone app but something simple that just syncs with home-base so I can do minimal things on the fly like view tasks, add to inbox, and check off one as I complete it. It would be ridiculous to expect to do everything on my phone and not have a desktop for heavy work. I require Pro on Windows because that's the only place practical to use full tools and edit the whole outline. I require Android as an extension for remote access because I cannot just pull a PC out of my pocket at the store when I "buy beans".