Unless I'm doing something wrong, beware that 3rd party apps like QuickPic, ES File manager, etc. will NOT be able to write, modify or delete files from your sd card. I've tried 2 different brands of sd cards that work just fine in other phones. Consider this: Other phones that are also running Android 5.0.2 such as the Galaxy S6 and HTC One M9 do not have this problem. The native apps on the Idol 3 such as "File Manager", "Gallery", etc. have no problem accessing and deleting the files. No reviews of this phone mentioned this problem. Would someone who has installed an external SD card please see if you have the same problem with ES (or Solid) file managers? The SD card like I saw shows under storage and native apps have no problem so it can't be the card(s).With only 16GBs of internal storage this is going to be a HUGE problem.