USB Flash Drive File Transfer is an Android app that allows you to hook up a USB Flash drive and transfer files between them without the need to have a rooted Android phone.
The UI is simple, the upper grid shows the files in your SD and the lower the files in your USB. Just drag and drop files to transfer them. USB Flash drives must be formatted as FAT32 but it is the more common filesystem in USB Flash drives
The app is pretty simple but if you are technically savvy the library working behind the scenes is far more interesting. It handles the USB mass storage stack (FileSystem, SCSI and Bulk-Only protocol) from the user-space, and I will release it in some days as open-source. So if you are interested stay tune! 🙂
It is still an early version. Some operations are still slower that they should be but I am working on improvements. If you find other errors and/or suggestions I would love to hear about them 🙂