A flash drive that can utilize space behind a mobile device is disclosed. In some embodiments, a body of the flash drive has three portions, a front portion, a back portion, and an intermediate portion that runs from the front portion to the back portion. A mobile device connector extends from a first end of the front portion, and a second connector extends from a second end of the back portion. The intermediate portion is configured to cause, when the mobile device connector is connected to the mobile device, the second connector and part of the back portion of the body to be located behind and, in some embodiments, adjacent to the back of the mobile device. This can enable part of the body to fit in a gap that can form between the back of the mobile device and a user's palm when the user holds the mobile device.