Tom Evslin is reminescing about Visicalc over in his blog, how it saved his bacon when he was road commissioner for Vermont.
I suspect there are my stories like this. I always liked the quote from Dan Bricklin, about people’s reaction to the program:

In those days, if you showed it to a programmer, he’d say “Yeah, that’s neat. Of course computers can do that–so what?” But if you showed it to a person who had to do financial work with real spreadsheets, he’d start shaking and say, “I spent all week doing that.” Then he’d shove his charge cards in your face.

(This from Licklider, T. R. (1989). “10 Years of Rows and Columns.” BYTE 14(13): 384-390.)
Pervasive computing – we seem to have forgotten how much this technology has changed our lives, how abundance of processing power is in everything.