Your wording isn't precise enough, or might not be, so to be 100% sure:
Have you already purchased EK with Google account? If yes, then you can use it on as many Android devices as you want, as long as all of them use that same account as main (or only one, there's bugs with account management, so sometimes Google can get confused with multiple accounts etc.).
If you bought EK on iOS, or PC, no, you'll need to purchase again.
You can ask Apple if they are willing to give the money you paid them to Google
That's two different shops, it's not possible to restore it, you can only transfer the safe game. It's a technical issue since steam Google and Apple don't work together, you have to buy for each platform separately (like buying a game for PC and ps4 and Xbox)