Useful but Smaller:
Mobile phone connecting the keyboard.mouse,USB memory sticks,Make the operation like computer.
Expanded cell phone memory
Phone directly connected USB drive for document reading,audio and video viewing,editing,moving,or even share,and so on.
Connect a mouse without a touch screen operation
Do not click on the phone's screen anymore,playing games easier to achieve freedom to operate like a PC
Before you purchase,pls make sure that your phone supports OTG function