killer app 

stands for killer application. Used to describe a game/application that really makes a system/computer.

Halo was the killer app for the Xbox

killer app by where am i? March 13, 2005

killer app 

"An application that proves the usefulness of the underlying technologies"

Defined by Jawed Karem in the speech "YouTube: From Concept to Hyper-growth" held at University of Illinois at Urbana-Champaign ACM Conference, Oct 21, 2006. (www.youtube.com/watch?v=nssfmTo7SZg)

A typical killer application:
- the first spreadsheet application

Killer apps in the internet domain:
- Wikipedia
- LiveJournal
- MySpace
- Flickr
- YouTube

killer app by Papy Jojo December 15, 2008

Killer App 

When at the click of a link sent via an app, someone’s digital device is virally infected or disabled, often with the terrorist sender or hacker able to retrieve the data stored on the recipient’s phone, tablet, or watch.

After John unsuspiciously clicked on a link in a WhatsApp fake member’s message, no one in the chat group anticipated that the killer app would facilitate the transmission of the Russian virus at such a lethal speed, which wiped out the data stored on all twelve members’ devices.

Killer App by Covido March 5, 2022

Killer app 

Mobile application with doubtful usefulness that gets downloaded and used by a very large number of people, often without a valid reason.

Hey, once you are done with Candy Crush, check out Quads and Flappy Bird, they are the latest killer apps to hit the App Store!

Killer app by n.tex January 25, 2021

Killed Two Birds With One Apple 

Similar to the phrase "kill two birds with one stone" this term means to complete two discrete tasks with a single action. The term traces its origins to a practice, originally made popular by aspiring major league baseball players on the Gulf coast of Florida, of hurling apples at the apparently limitless number of pesky seagulls.

As Mariah's girlfriend walked in on him banging her mother, Mariah thought to himself, "I've just killed two birds with one apple"; I've both fulfilled my MILF fantasy and ended this shitty relationship.

Killed Two Birds With One Apple by MGDRehab March 11, 2011