A mobile app is a computer program designed to run on mobile devices such as smartphones and tablet computers. Most such devices are sold with several apps bundled as pre-installed software, such as a web browser, email client, calendar, mapping program, and an app for buying music or other media or more apps.

The concept of the app – a neat little piece of software performing a particular function, typically on a mobile phone or similar hand-held device – has taken the world by storm in the last 18 months or so, catapulting the word itself into mainstream use. Two or three years ago, use of app as an abbreviation for application would largely have been confined to specific technical contexts.

In January 2011, the American Dialect Society named “app” the word of the year for 2010. That action alone says a lot. Being named word of year signifies that a term is trendy and growing in popularity. However, just because the use of a word is growing, we shouldn’t assume that everyone knows it — yet. That’s because being named word of the year also implies that the word is newly prominent.