hmdshfq, Feb 11, 2019 : Those who are living in China and who have switched their OS from H²OS to OOS. Can you guys still use the cards app in OOS? I use the Beijing metro everyday and it is a must have app on my android. It is only for this reason that I am stuck with H²OS. If the cards app work on OOS then I would be more than glad to make this switchover.