Slide15 is a sliding-tile puzzle you can play without leaving ChatGPT. Ask for a puzzle and a board appears in the conversation: swipe, tap or use the arrow keys to slide the numbered tiles until they read in order. Every puzzle is shuffled with legal moves, so it can always be solved. New boards on demand, a timer and move counter, a short how-to-play primer for first-time players, and full localisation in English, Russian and Spanish. No account is needed and nothing is collected beyond anonymous usage analytics. The same game is free on the web at slide15.com and on iPhone and iPad.