Colloquialism for a use or application for a technology (or a software application), which is so useful and so rapidly adopted that it drives a large increase in sales of that technology. In desktop computers the original killer-app was considered the spreadsheet and especially the first widely used spreadsheet known as Visi-Calc developed by Dan Bricklin and Bob Frankston; later killer apps were easy to use word processing packages such as WordPerfect; networking software such as Novell Netware and most recently the widespread popular adoption of the Internet, then video streaming and online multiplayer games. In cellular phones, SMS or short messaging service has often been described as a killer app, followed by push e-mail, then cameras, then front facing cameras (for video calling) all combined with faster networks, and widespread adoption of WiFi. Many commentators ascribe post 2000s downturn in the technology industry to a dearth of killer-apps, although it has also been noted that excessive reliance on killer-apps caused technology to have a pronounced boom-bust cycle. See Nifty-App
The boom-bust cycle is often also ascribed to the overbuilding of production capacity for products such as microprocessors and in particular memory chips; the resulting oversupply causes prices to collapse. However, the then dramatically reduced prices for previously expensive components can often drive falling prices for devices more-capable of running newly developed applications that make heavy use of, for example, memory, leading to their popularisation and widespread adoption and an ensuing boom.