As far as changed your life, there are not too many that i really love, that made a massive difference to how i do things. But there is one:

Paperless_ngx

ALL of my paper work, receipts, transcripts, tax, shares, council rates. Everything goes in there. We no longer have paper lieing everywhere (well, my wife is another matter, still keeps grocery shopping reciepts...). when i get soimething in the mail, i used the paperless app to "scan" it, upload it, then bin the paper.

An actual life change that i didn't know i needed.

How is your work flow from scanning to paperless? Does it support some kind of upload folder?

Yeah paperless supports an upload folder. My scanner has an ability to scan to a network drive, so I scan things onto a shared drive on my homelab box, paperless consumes the scanned PDF and places it into the paperless “inbox”.