I am also ensuring the game runs on most phones. The unity wrapper is going to be primarily made for WEBGL, meaning for website running; there is no binary, but we might make one later. I want to focus on web and phone web.
The rule on phone is make it vertical, but on iPads or tablets which is also in the works I want a more open design we're aiming primarily for a semi responsive web-app.
About devices, now this is a touchy subject, for now its, not all phones, most iPhones, some androids, if you can play itch.io unity games on the phone you are pretty much 99% probable to play this, we will use cookies to save, and think of a way of file transfer. Stay tuned.