Tap Start and Dudu sits with you for 25 minutes (you can set 5 to 60, and a 1 to 30 minute break). When the time is up Dudu celebrates, tells you to stretch or drink some water, and has a snack while the break runs. Each finished round goes on the board: today's count and a chalk tally for the week. Pick how to tally: four lines and a slash, the 正 character used in China, Japan and Korea, or a square with a diagonal. The timer runs on timestamps, so it stays right if you switch apps or lock your phone; a round that ended while you were away still counts. Everything is saved on your phone. Dudu is drawn with the Y Build app's own sprites. The cover art was generated with AI.