Connect OP-1 to Phone Via USB

So in the past I’ve used the apotop wifi thing to connect my iphone to OP-1 to backup files when on holiday etc.

Now I’ve went and got a Samsung phone. Can I connect directly with the OP-1 using a cable? and be able to drag n drop files?
What is the kind of cable I need to get? (link?)
And do I need a specific app?

USB OTG cable

You can find them for under $2 each if you look around. No specific apps needed, this is how I back up files to my Galaxy S5.

You’ll see the usual 4 folders, but 2 other folders may show up when connected to the phone (LOST.DIR and ANDROID). Both of those can be deleted and the backup can still be reloaded to the OP1 easily.
I updated the OP1 firmware with this setup too, no need for a laptop or desktop computer.