The app gives you full control of your skydrive. Essentially all of the functionality that you get through the skydrive website, but in a much nicer and easier to use package.
Or to break it down a bit, the app allows you to create folders, organise and delete files and folders, and send links to them as well. Oh and view folders/items that have been shared to you as well. It's a nice app I think, find it very useful for organising my documents on the go.