Puzzle Together Multiplayer Jigsaw Puzzles on Steam
These websites will let you do a puzzle with your friends
Parent Review: Jigsaw Puzzles.io - Little Day Out
PPT – Jigsaw Puzzles Clash releases first-ever point based multiplayer jigsaw puzzle game, that plays on one puzzle board! PowerPoint presentation | free to download - id: 8c4c7c-OGRmZ
You can put together virtual puzzles with your friends
Multiplayer Jigsaw Cooperative - Apps on Google Play