I never considered making any landscape based card games until after I added a feature in my mobile game DroidGOX Card Games to have leaderboard via Google Play Games and finding out that All in 15 is a top hit because of its easy game play.
So the first games to be featured in landscape mode is Total 11 and Mathematics. Both games are very easy to play.
In Total 11, you pick any number of cards that add up to 11. Jacks, 10s, Queens and Kings are considered 10 in value so make sure you pick cards selectively to get as many points as possible. The more cards that add up to 11 the more points you get to score.
In Mathematics, 2 cards given to you will be considered the value you need to add up by using 7 available cards and using mathematical equations to get the desired result.
These 2 games are not time based so take your time and plan your cards accordingly.