It's a program. "App" is a word, short for "Application Program," publicized by Apple for its handheld computers that masquerade as (and are euphemistically called) "telephones." "App" effectively means "proprietary closed-source program that talks to proprietary walled-garden programs running on someone else's computer, and acts as a spy sending all your sensitive data to who-knows-where."
No-one ever called a real program an "app" before that, did they?
No-one ever called a real program an "app" before that, did they?