iOS Simulator can be used to test mobile applications. Xcode tool that comes along with iOS SDK includes Xcode IDE as well as the iOS Simulator. Xcode also includes all required tools and frameworks for building iOS apps.  However, it is strongly recommended to test the app on the real device before publishing it.

For launching an application, we will need to create an intent that explicitly defines the activity that we wish to start. For example:

Code

        Intent intent = new Intent(this, MyTestActivity.class);

        startActivity(intent);

Intents are created to define an action that we want to perform and the launches the appropriate activity from another application.

Code

        Intent intent = new Intent(Intent.ACTION_SEND);

        intent.putExtra(Intent.EXTRA_EMAIL, recipientArray);

        startActivity(intent);

Each application gets its own Linux user ID and virtual machine which means that the application code runs in isolation from other applications.

Android Application Architecture has the following components:

> Services - like Network Operation

> Intent - To perform inter-communication between activities or services

> Resource Externalization - such as strings and graphics

> Notification signaling users - light, sound, icon, notification, dialog etc.

> Content Providers - They share data between applications

In general, a Nine-patch image allows resizing that can be used as background or other image size requirements for the target device. The Nine-patch refers to the way you can resize the image: 4 corners that are unscaled, 4 edges that are scaled in 1 axis, and the middle one that can be scaled into both axes.

The following are steps to be followed prior to actual application development in an Android-powered device:

- Declare your application as “debuggable” in your Android Manifest.

- Turn on “USB Debugging” on your device.

- Set up your system to detect your device.

User defined functions can be created into the Microsoft spreadsheet. Spreadsheets can be customized according to the user needs by using VB applications. To create visual basic functions useful for spreadsheet you need to click Tools and select Macros where you will need to click on Visual basic editor.