There are some issues .... The GIN, BIG GIN, and KNOCK buttons are in the exact same location and are the exact same colours. They should each be more easily distinguished by position or different colours. Also, the KNOCK button should have the remaining score if you do knock. The screen shows your current score but not what the score would be AFTER your discard, so you are always having to subtract in your head.
I would buy it if it were reasonably priced.
Jetranger_Pilot about Gin Rummy Deluxe - The Best Classic Card Game, v1.0.1