One short hand between meetings: picking cards around your work rhythm
Rounds of one to three minutes, clean stopping points, and no streaks.
The gap between two meetings is rarely longer than ten minutes and almost never arrives on schedule. A card game that fits that gap must pass three tests: a round with a clean ending, a game that remembers its state if you close the tab mid-hand, and no daily-reward machinery pulling you back. Those three rules remove most of the catalogue of the big portals, which is exactly why this page exists.
The two-minute rule: if a hand cannot finish before your next meeting starts, do not start it. Choose rounds of one to three minutes, because a short hand lets you stop at a clean boundary instead of abandoning the middle. Turn-based games suit this frame better than real-time ones, because the meeting clock does not respect the game clock.
One thing to avoid: streaks. Any mechanism that rewards returning every day starts steering your calendar instead of serving it. The best card game for working people is one that does not know who you are: no account, no streak, no notifications, just the deck and your ten minutes.

Magic Battle Online
Candy Chain Master