I just use Google+ to make backups of all my photos. You can tell it upload as soon as the photo or video is taken, only on a wifi network, or only when charging if you care to manage it in these ways.
It doesn't do a great job of organizing the photos - it does it by the day when the picture or video was taken. I also have no experience with using different devices with the same account, but I assume it will organize all photos under the day they were taken irregardless of device they were taken on.
You can download all photos from your Google+ account.