The following tools are used to interact with mobile devices and mobile applications:
Salesforce platform mobile services in Force.com: This service provides a way to access enterprise data by leveraging standard web protocols (REST API). It allows you to expose business data across any device. Salesforce platform mobile services include Mobile SDK, identity services, social engagement, geolocation services, Analytics API, mobile design templates, REST API, and JavaScript frameworks.
Salesforce Mobile SDK: This is an open source pack of familiar technologies such as REST API and OAuth 2.0. It allows you to build rich mobile applications that use Force.com and Database.com as the backend. It supports the building of HTML5, native, and hybrid applications.