Originally Posted by
YuropFlyer
At least in Shanghai you can get an electronic metro pass stored on your phone. Personally I prefer the real pass (just like I do prefer to use a metro card in London or Singapore where you could use any NFC credit card for single-rides instead) - but for a single ride, afaik you can't use a "phone-pass" yet.
I figured it was something like that because I've seen a few people using their phones instead of cards at the subway.