Playing cards can be difficult for people without good fine motor control. Often, holding the cards is a more significant challenge than the game itself.
This design was at the intersection of "free" and "quick." The only supplies needed are two discs and two paper clips.
Step 1: Stack
Stack the first two discs you can find.
Step 2: Clip
Clip the discs together through their spindle holes. Put the two clips in opposite directions.
Step 3: Spread the Discs
Slide the discs apart until the clips offer resistance. This will provide a gap to slide cards against.
Step 4: Play!
Slide in some cards and have at it. The design can hold pretty large hands, but if cards are falling out, add clips for more tension.