The same way you find them on your sdcard or micro-sd. settings/storage or file manager. The drive should mount automatically. You should unmount in settings before removal.
Hi Astrix. I bought the app. Installed it. Plugged in my memory stick through the OTG cable. Nothing happened. I can see all the images on the external sd card, but can't see the memory stick at all. Do you think there's something wrong with the cable?
Don - It would be helpful to have the complete description of your tablet. As tpaine indicated, most tablets use the OTG cable, the operative words are "most tablets."