Vivo v3 is use android lollipop for factory default operating system. at the time this phone release, I was expecting to have android marshmellow for default firmware. but using android lollipop at VIVO V3 can run all features without problems. one more minus point of VIVO V3 external memory simcard slot is using the same slot with simcard 2 network provider, therefore we have to choose use simcard slot 2 for network simcard or external memory micro SD.