Killer application. Tech industry jargon for an Short for the word application. An app is a small software a... so obviously massively useful to someone that they will rush out and buy it immediately, even purchasing the All the physical parts of a computer or device. need to run the app, if necessary. In 1979, VisiCalc was considered the first Killer application. Tech industry jargon for an app so obvio... and helped drive sales of the Estimated to be the most valuable brand in the world, Apple ... More II, the only computer that could run the software. In 1996, Super Mario 64 was the killer app that brought players to the Nintendo 64 gaming console. Today killer apps tend to run on most devices.