A new picture arrives every day at midnight UTC, cut the same way for everyone. The week sets the size: 25 pieces on Monday, 36 on Tuesday, then 49, 64, 81 and 100, and 144 on Sunday. The picture guide shows it whole before you start; studying it costs nothing, because the clock starts with your first move.
Drag a piece onto the board, or tap it and then tap its slot. A piece only goes into its own slot, on the edge or beside a piece already placed, so start with the frame. Put pieces down anywhere to sort them; Shuffle re-deals the tray, and Edges narrows it to the ring you are building. Your pieces and time are kept, so you can leave and come back.
Yesterday's puzzle, and every one before it, stays in the archive, with a numbered key to its solution.