Mobile app development is a term used to denote the act or process by which a mobile app is developed for mobile devices, such as personal digital assistants, enterprise digital assistants or mobile phones. These applications can be pre-installed on phones during manufacturing platforms, or delivered to provide an "application-like" experience within a web browser. A cryptocurrency wallet stores the public and private keys which can be used to receive or spend the cryptocurrency. A wallet can contain multiple public and private key pairs