Generally I can recommend as an adapter to take a flexible cable instead of a rigid plug, since with the latter usually stick out further and you can damage the sockets before, if you come by mistake against the plug.
A little hint for those who are confused about the difference between USB On-the-go (OTG) and USB host function: USB On-the-go means a direct communication between USB devices, that is, one of the devices assumes the (always required at USB) host function.
In plain language: A device that supports USB OTG is always a device with USB host function; with respect to the desired functionality, the terms are so synonymous in some ways.
