Android
Android is an open source and Android SDK is
applicable in heterogeneous platforms with well documented
API . Android is very different from the platform used in
iPhone. Android is practically designed for a wide range of
mobile systems and also the programming environment used,
which is Java programming language . Android
application consists of a set of activities which included the
user interaction that may have one or more input screens. For
example, select a contact from the internal address book is an
activity. User may flip through the contact list or may use a
search box to find the specific contact number. Many actions
are combined to become an activity. Activities have a welldefined
life cycle and can be invoked from other activities even
activities from other applications. Besides a variety of widgets,
the declarative description of user interfaces is also allowed in
Android. XML files describe the relative layout of a user
interface which simplifies internationalization and also allows
rendering the user interface on different screen resolutions.