This is a game in the checkers/draughts family played on an 8x8 board, using 24 pieces aside.
This game originated from asking two simple question regarding Anglo-America checkers: First, why is only half the spaces used? Second, what would happen if you used all 64 spaces of a checkerboard?
End result is a game in the checkers/draughts family which tries to remain true to regular checkers, also accounts for the full use of the board. Checkers move as they do normally, but they also jump both diagonally and orthogonally. In addition, the King piece gains mobility to be like a King in chess.
Edit: Please note the PDF rules do not show orthogonal capture moves for Checker pieces. They do capture that way, in addition to diagonal.
Editi 2: Playable on Tabletopia in this collection:
https://tabletopia.com/games/alquerque-and-friends