Not sure exactly what you're looking to do. But Dropbox has always worked great for sharing and transferring files for me. Mostly because it's cross platform. I use it on iOS, Android, OS X, and Windows. And though a web browser if I'm not on my device.
Say I need to access a spreadsheet I have on my MacBook, I just save it to Dropbox and open it on my iPhone. Voila.
You could also use Box, Google Drive, One Drive, etc...
Then once you've got access to the document, you can open it with any compatible app. Like Pages for Word documents. Or Adobe Reader for PDF's.