https://lovattspuzzles.com/online-puzzles-fullscreen/sudoku-fullscreen.php
the sudoku page : https://lovattspuzzles.com/online-puzzles-competitions/daily-sudoku-puzzle/
all their games : https://lovattspuzzles.com/online-puzzles-competitions/
http://www.metro.us/games/sudoku/
iframe source for 13 DEC - http://data.puzzlexperts.com/puzzleapp/static.php?psid=100000475
beta https://staging.puzzlexperts.com/YouPlay/api/game/4/html
similar - http://www.youplay.com/
origin - http://www.pipiscrew.com/?p=6379 puzzlexperts-sudoku