I've still not really found anything to accomplish this.
The end goal here was because I use Juice to automate downloading podcasts, which I download to my Dropbox so that I can listen to them across my devices. After a while, the files began to suck up a lot of space and I don't necessarily want to delete them because I still may have not listened to them, would rather just compress them in a .rar or something like that. With an application like this, I could have it monitor that podcast directory for files that are a certain age old from today and have them automatically compress. It wouldn't need to monitor folders in realtime because then we'd be compressing files one by one, rather something that I could run manually, or on a schedule, every few days.