I don't have any need for your email address. You could put "[email protected]" in there if you want. The account is for tracking progress and eventually there is a paywall. I give 25 puzzles for free for every puzzle type + every difficulty, but after that, you pay a couple bucks to unlock the rest of the puzzles. Helps pay the server fees. Although I've made $0 so far and that's fine really. This is mostly just a fun little site for people to use.