Apple is notoriously poor at this. Just look at the Apple Watch, or unreleased APIs of iOS working with OSX for chat and phone calls.
Google is only marginally better. They're usually late with iOS support and it can be incomplete. It took how long to release iOS support for android wear? Plus, if I don't have a google account, I want to still get maps and services.
I don't want vendor lock-in is the point here. Amazing though that we don't have some sort of standards body out there that could help with these sorts of things.