Here is what I am looking for.  Maybe they don't make something to do it, so give me suggestions.  I'm not up on all the gadgets for this stuff, but would like a device to relieve the memory use on my phone.  I'm going on a trip for a month and won't have cell service so I'm trying to download some things to pass the time before I go.  My phone is a galaxy s4 and the memory is used up.  I would like a device to transfer things to so I can free up memory on the phone for new pics or podcasts or whatever. Basically like a thumb drive for external storage.  Do they make a device like this?  If not, what kind of MP3 player or whatever would best suit me?   Thanks

If I need to help out with more info, ask as, again, I'm not up on all that stuff.