Sync w/o proprietary software as USB drive

[ykgoh]

Which smartphone OS allows a USB connection to a PC/laptop, mount as USB drive to transfer and sync data like music, video and files? Only Android?

Windows Phones require the Zune and Windows Phone App to transfer data in their proprietary protocol. And I'm guessing iPhone uses the iTune software to do the same.

Is my understanding correct?

 

[ykgoh]

Just to add, I think my question is related to USB On-The-Go (OTG) support.

 

[DigDub]

android allows it. I think the latest windows phone os also can, not sure? iphone need iTunes.

otg is another thing. otg means the phone becomes the computer, can plug a otg cable with card reader to the phone usb port and transfer files to the phone from a memory card.