Since becoming disheartened with the exclusivity clause in Amazon's KDP Select program, I've looked into expanding the release of my book into other formats. Nook and Kobo both offered quick and simple sign up methods, but according to a note on this page: https://www.apple.com/uk/itunes/working-itunes/sell-content/books/ I require a Mac computer or an agreement with an "Apple-approved aggregator" to be able to publish on iBooks. Seems to me like this is an unnecessary requirement, whichever route I pick. I can't afford a Mac computer, and I don't like the idea of a third party between myself and the Apple Store. Has anyone else here published on iBooks without a Mac computer?
I just glanced at one and it looks a lot like SmashWords print on demand: https://www.draft2digital.com/ I suggest you find an aggregator or two then do a Google search for reviews.