It's not super automatic but CloudBerry Explorer for Azure [1] is free and has a pretty good folder sync feature. I basically just keep all my photos and videos in single a folder on my desktop. Whenever I copy my families phones or tablets to my PC I just run the saved sync, it's usually pretty quick. I have over 90 GB of stuff so it actually took a long time for CloudBerry to analyse the folder for the first time, after that it figures out what's new and needs to sync pretty fast.
