Mentioning "Not affiliated with Nintendo" is also a good way to be upfront. I don't understand why I can "Draw cards" on your website if you want to make it a resource for the Pocket game.
I agree with parent comment that it looks like a phishing site and it's not honest about whether it's a fan game or a malicious copy of the official one.
I agree with parent comment that it looks like a phishing site and it's not honest about whether it's a fan game or a malicious copy of the official one.