You can plug an iPhone USB flash drive into your phone via a lightning port. The device may also feature a second end that has a USB connection that can go into your computer for file transfer. To access the interface to transfer files, there are specific apps designed for iPhone USB flash drives. The preferred app to use is contingent upon the iPhone USB flash drive that you purchase. Different brands may make use of different apps or have a dedicated app. Drives that have a USB end, in addition to a lightning end, offer you the benefit of compatibility with a broad range of laptops and computers. This feature could be useful to you if you plan to transfer files to or from a computer that only is compatible with USB devices.