Flash NAND Storage Module with female USB 3.0 Output that works with Android, OS X and Windows

Looking for an electrical or computer engineer to design and develop a storage solution for a gadget, the storage module is a stand alone module with a usb 3.0 female output that connects to external devices by OTG. (Windows, MacOS and Android) and allows the user to transfer data between the device and the module (Android App will be developed by us separately). It will be a NAND flash storage, we prefer using Toshiba chip with integrated Microprocessor, but open to any ideas. The storages will be 64GB and 128GB. The output has to be a female USB 3.0 that connect to the devices using appropriate cable. In simple words it's a USB Storage (OTG) which connects to the mentioned devices. Size has to be 1.4cm x 3.75cm or smaller. *** freelancer is in charge of hardware and software (firmware drivers) *** *** Previous experience with flash NAND storage design recommended but not required ***