KEYBORED  What was a pleasing novelty when it first emerged has become an indispensable program to those of us warehousing any significant number of PDFs in the chaos of folder hierarchies. It's especially useful for those of us who find or make our PDFs serendipitously in the middle of doing something else (and therefore can't always file them precisely and wisely), or for whom a PDF saved appropriately for one purpose becomes relevant to another one later on. Such is the life of writers, researchers, teachers, among others. For us, YEP has become the gateway to the riches buried in our HDs. Those who can remember everything without ever forgetting don't need it, of course. I do.  
(Version 1.7.5)