Dropbox is a very well know file sharing service service. It works across all major operating systems include mobile phones. I use it to keep my projects in sync across the multiple PCs I use in different locations. With Dropbox after you make a change to a file it is then uploaded and distributed out to your other machines as soon as they are connected to the internet.
With the mobile app you can download any the files in your Dropbox on your mobile device. You can also upload files to it as well. I upload my backup files for different phone apps right up to my Dropbox. This allows me to be able to wipe out my phone without losing a thing. If you don’t have a Dropbox account and want to get one you can follow this link: http://db.tt/L1fAyGt