Mobile apps for the general consumer do just about anything. As the enamel suggests, they are run on mobile devices and are application that can pretty much do anything.
Some popular apps:
As with mobile gaming, mobile apps have exploded over the last few years. One of the main driving factor is costs. While they generally have less functionality to desktop software, comparable apps are a fraction of the cost, many starting at a dollar or less.
The best comparison of mobile applications is here: http://www.telegraph.co.uk/technology/mobile-app-reviews/