Yes. It work with iPhone. Depends on your external storage, you might need to purchase the iPhone Camera connection kit, so you have enough power to drive the external storage devices.
Note, the device need to be formatted as FAT32, exFAT or HFS or AFS.
I guess not Apple MFI, but working fine. I've got the original Apple adapter and the Chinese adapter, no difference. I can use USB-Sticks, HardDisks etc. (2.5" HardDisks with an active USB-Hub between).