Well, it is not using Tarsnap as a backend and it seems that you have to add folders on the first launch, that is definitely not what I am looking for :)

Time Machine and Backblaze know how Mac OS is architectured and backup everything but useful files (logs mainly).

+1 for ARQ. Best S3 backup I have found on OSX. Sorry TARSNAP, I will only backup to an account I control.