Just picked up a BuckStruck outdoors Trail Camera Card Reader. All it consists of is a dongle that plugs into the USB port of an Android phone and allows you to read external SD cards and USB flash drives. I think there is a iPhone version as well. It works really well. I was able to read a SD, Micro SD and USB flash drive with no problems at all. I did try to use it with an external hard drive but it would not recognize that device. I did not have to install any app or change any setting on my phone but they do indicate that you may have to enable the mass storage options if they are not already turned on. I just happened to stumble upon it on Amazon when looking for something else and thought I would give it a try. I'll definitely be field testing it when I get my trail cams hung.