A mobile phone application, commonly referred to as an app, is a type of software designed specifically for use on mobile devices such as smartphones and tablets. These applications can range from simple tools that perform basic functions like making calls or sending messages, to more complex programs that provide users with advanced features and services. Apps are typically available through various app stores and can be downloaded onto a device by the user. The term "mobile phone application" generally refers to any software program designed for use on mobile devices, regardless of whether it is a game, utility, or other type of application.