Puzzled! is free and stays free. Everyone gets every picture in the library, unlimited multiplayer games, puzzles up to 1000 pieces, and one picture of their own — without paying anything.
CHF 3 per month, or less on the yearly plan. Payment is taken by Stripe on their own pages, so card details never reach this site. Cancel whenever you like from your account and keep everything until the period you paid for runs out.
It also keeps the game running: the pictures, the database and the servers are paid for by members rather than by tracking anybody. Learn how to play first, if you would rather.