History that's easy to remember or search for if you don't is all I need to back up not a claim but a fact.
Windows XP ran PROGrams from a PROGrams menu shortcut in the START menu while the Mac ran APPlications launched from the APPlications folder they reside in.
I would like to point out if you ever dug threw MS folder structure you would see that they had folders with titles like Application data, I know it was in windows 95 and XP. Now general user may not see is but in the industry among devs App and Applications was a commonly used term.
Just because the general public did not use the terms does not change the fact it has been a generic term for a very VERY long time. Heck I know the term was used in the 80's when refering to Lotus 123. Lotus was called a Killer APP. OMG that App word was used in the 80's...... It is generic end of story.