Last December, Dan Grover summarized the unique mobile app UI conventions he'd spotted since moving to China the summer before to work for Wechat, a Chinese mobile messaging app that also incorporates a wallet, Evernote-style functionality, a games platform, a people-finder, a song-matching service, and, of course, an email client.
Grover's work highlights many UI elements that have no analog in English-language/European UIs, including the "indeterminate badge" (an orange dot that means, "here is new content" or "your app is ready to be updated" or "you turned something off"); super-popular Android ROMs, skinnable apps, and a weird trend to turn on an assistive feature that seems like it would really get in the way:
Probably half of all iPhone users I see have the "Assistive Touch" option turned on, which makes a floating button appear on your screen at all times. This button, besides being annoying, emulates the hardware "home" button, as well as multitouch gestures for users whose impairments prevent them from performing them.
Nobody can give me a straight answer on why they, a person with two functioning hands and a full complement of motor neurons, enabled this obscure accessibility setting. Answers range from protecting their investment on the phone by not wearing out the physical home button, to it just being fun to play with when you're bored.
Chinese Mobile App UI Trends [Dan Grover]