Much like a desktop or laptop computer, mobile devices organize icons and widgets on multiple screens for easy access. These are called the Home screens. One screen is designated as the main home screen, as shown in Figure 1. Additional home screens are accessed by sliding the main home screen to the left or right. Each home screen contains navigation icons, the main area where icons and widgets are accessed, and notification and system icons. The home screen indicator displays which home screen is currently being used.

Navigation Icons

The Android OS uses the system bar to navigate apps and screens. The system bar is always displayed at the bottom of every screen.

The system bar contains the following buttons, as shown in Figure 2:

Google search

Android devices often come with a default Google search app preinstalled. Touch and then type text into the box to search the device and the Internet for anything. Touch the microphone icon to enter the search using speech.

Special Enhancements

Some manufacturers add functionality to the Android OS. For example, some Samsung Android tablets have a feature called the Mini App Tray, which contains shortcuts to apps that can be used at any time. The Mini App Tray is opened by touching the arrow at the bottom of the screen. This feature is useful because the user does not have to navigate away from what they are doing to run a specific app.

Notification and System Icons

Each Android device has an area that contains system icons, such as the clock, battery status, and radio signal status for Wi-Fi and provider networks. Apps such as email, text messaging, and Facebook often display status icons to indicate communication activity.

To open the notification area on Android phones, touch and hold the top of the screen and swipe your finger down the screen. On Android tablets, touch the notification and system icons at the bottom of the screen, as shown in Figure 3. You can do the following when notifications are open:


Instead of using the standard Android interface on its phones, HTC designed the TouchFLO interface over Android. With TouchFLO, use a special menu accessed by dragging your finger up the screen and then select common tasks by moving your finger left or right. TouchFLO was replaced by TouchFLO 3D. TouchFLO 3D had a collection of tabs along the bottom of the screen to easily access tasks. TouchFLO 3D has been replaced by HTC Sense. HTC Sense uses desktop apps and widgets, but has many interface modifications exclusive to HTC devices, such as locking screen apps and widgets and 3D home screen effects.