The naztech Xtra Drive SD Card Reader is just that - a reader without its own internal memory. This app finds my "external memory" (a provided 16GB micro "SD" card as well as a 32GB card plugged into it) on my 16GB iPhone 5, on my 32GB iPhone 5S and on my 64GB iPhone 6 - all running iOS 9.3.1. Plugging the Xtra Drive into a 32GB iPad Air 1 this app DOES NOT FIND that exact same external memory - a let down as I create online video content and the Xtra Drives appeal to me was quick-swapping media to and from my iPad (which I use for mobile creating and review.) My memory cards were already FAT32. None were NFTS but you can check the format of yours by right-clicking it in Windows explorer and then clicking properties in the drop down menu. Media transferred from the reader to your device doesnt show on your camera roll so youll need this app to manipulate it and it will take up memory on your device, even if cloaked. Playing back media directly from the card in the reader it constantly buffered, compelling me to transfer it to my device for smoother playback (so much for saving space). The lighting connector on the Xtra Drive protrudes from its housing less than it does from an Apple charge cord so most iPhone cases will have to be removed to use the reader because the shoulders of the Xtra Drive bump into the case. iPad cases are usually book-types and seldom encase the body but ah..the irony, this app and reader didnt work for my iPad Air. Lastly, despite the name Xtra Drive, without its own internal memory it is only a u-style micro "SD" card reader (theres a USB end for the PC). Card readers cost only few dollars anywhere and "aircraft aluminum" LED flashlights are 5 bucks by the register. Yet, this thing is expensively priced - $80 where I found it and the store internet-price-matched it down to $66 for me. Its a good concept - product and app - but it needs to go back in the development oven a bit longer and return with a more realistic price. Save your cash and seek a cheaper way.