I wasn't going to post on this but I've changed my mind. I think there are a few apps that will let you transfer files between iDevices but I've not tired them. It's pretty easy without any of these apps. I have activated my iCloud email account on all of my iDevices and created an Archive folder. All I have to do is email the items to this account and store the files in the cloud. Then, you can either access, use or download it from there.
You can do the same with a Gmail account and get WAY more storage that way too... I have both and it's free. It's an unsophisticated solution and may not work for your particular needs, but it works perfectly for me.
Sent from my iPad 3