I created a second Apple ID in the UK, as described in
this article. I couldn't find anything about Apple punishing such behavior, but still, do this at your own risk.
With the second ID, I could download the game, then switch back to my usual ID and play it. I couldn't buy Premium though. I got an error saying the original purchaser had to do so. The prices did show up in USD: $1.99 for 1 month, $9.99 for 1 year.
I chose using a second ID since I read that if you want to change your ID's region, you must cancel all subscriptions first. I did not want to chance losing any of my cloud storage. It was still annoying that logging out of my regular ID caused some files to be deleted from my phone (though I was told they are all in the cloud). Microsoft and Sony make it a lot easier to change IDs. Even Macs allow for multiple accounts. I guess it's just iOS that's locked down so much.
The interface and challenges look totally different than the Win 8 version. I'm doubtful any progress is going to ever carry over.