I went to the bus stop but realized that I was still too sick to risk the commute. I could have worked from home, but that is only for people with higher salary. So sorry, but I'll have to wait. Perhaps I can go there later in the day, perhaps not.
I wish I had known of this program months ago. I have two hard disks each with a couple hundred gigabytes of files. From time to time a file is added to one or another of them. In the past, I had to overwrite two hundred gigabytes of already perfectly fine files in order to get the changes (or press "n" for half an hour or two). Yay for syncback! Also, it is free.