Best USB app- dont look further
I use a PC, and dont enjoy the control iTunes has over my life. I installed a program on my computer called iFunbox that allows manual file transfer of files drag and drop style to this (and other) apps. Wifi transfer is also easy from anyones computer using the IP address. A true USB use of the memory on the idevice. I have loved this app since I got it last year. Note- I believe I did buy the full version, and the new update it a little cluttered, but that does not effect my 5 star rating.
tilleyroad about
File Hub by imoreapps, v1.8.4