I like the game but unfortunately Nintendo really does suck when it comes to online accounts. I had signed in on my iPhone then also set it up on my ipad. After finishing a few levels on the iPad i went back to my phone. The phone let me finish a level, THEN came up and said 'cant progress as you're signed in on another device' and the app crashed. what the fuck is the point of signing up for an account if it doesnt…
It's an organizational problem, and one that's not going away anytime soon.