An application is a software designed to do a specific job. The word ‘app’ is an abbreviation for ‘application’. An app enables you to do something specific, like paint, draw, read maps and barcodes, take photographs, play games, watch and edit videos, and a lot of other activities, within the technical limitations of your device.
An app works in pretty much the same way as the software does on a desktop or laptop. However, because the computing power and memory of a smartphone are generally less than a standalone computer, the capabilities of the app are limited than a similar software running on a PC.
Most desktops do not have touchscreen, while all mobile devices have it. This changes the way the user interacts with the device. Instead of a keyboard and mouse, the user taps on the to display, which works both as an input device as well as an output device.
Apps are designed to work on different operating systems used by various devices. An Android app is developed to work on phones, tablets, or other gadgets that run on Android OS; whereas, iPhone apps can be used on iPhones that use iOS.
For better running of the apps, the internet connection speed must be fast so that the app can be downloaded easily from the Google Play Store on Android phone or through App Store on iOS.
Types of Apps
Apps can be broadly classified as desktop apps, web apps, and mobile apps.
Desktop Apps
These apps can be used on a desktop or laptop. Generally, they do not need web access and run independently on a computer. To run a desktop app, it must be first installed on the desktop or laptop.
The installed app is represented either by an icon on the computer screen or item on the Start menu. Examples of desktop applications are Word Processors, Spreadsheet, Paint, and Notepad.
Web Apps
These apps require an internet connection. They are usually browser-based and stored on a remote server. Users can access them like any other web page
. Web applications require minimum device memory as the application lies on the remote server. These applications can be utilised at any point from any device through the internet. For example, Google Maps, Instant Messenger, etc
Mobile Apps
These apps run on a smartphone or tablet. Mobile apps have responsive web designs to adapt to the much smaller screen sizes and orientation of the mobile devices. These apps are usually small in size as mobile devices have limited memory.
Some mobile apps may come preloaded on cell phones or tablets. Keeping in view the device independence feature, software companies nowadays make diverse versions of the applications to be used as desktop apps, web apps, or mobile apps
Downloading And Installing An App
The following steps will help you download and install an app on your mobile phone or tablet:-
- Tap on the Play Store icon on the screen of your device
- In the Search bar, type the name of the app that you wish to download. If you do not know
- It will display a list of relevant apps. Now, select the most suitable one by tapping on the name of the app.
- Additional information about this app will be displayed, for instance, whether any fee needs to be paid. Check out the reviews and comments of the previous users. If they meet your requirements, tap on the INSTALL button to install the app on your device.W1
Developing Your Own App
Looking at the different apps available on the Play Store is an amazing experience. It may give you the impression that it is very difficult to make your own app, but it is not so.
There are several sites that allow you to make your own app in a very short span of time. Let us use the MIT App Inventor to develop an app. It is an open-source web application originally provided by Google and now maintained by the Massachusetts Institute of Technology (MIT).
It is an easy and innovative platform to introduce programming and app creation to beginners. To develop an app using App Inventor, follow these steps:-
Step1:- Open a browser, and type the following URL in the Address bar: www.appinventor.mit.edu
Step2:- Click on the Create Apps! button in the top-left corner.
Step3:- Sign in with your Google account
Step4:- After successfully signing in, accept the Terms of Service policy.
Step5:- The welcome screen appears. Click on Continue. You will get a new window, giving you options to go through the tutorials or start a new project.
Starting a Project
You can choose the Start a Blank Project option in the previous window or click on the Start new project button under the Projects drop down menu to start a new project. Assign a new name in the Project name field and click on OK.
Designing an App
When you start a project, you get the Designer window, by default. The Designer window is used to design an interface of an application. Notice, the Designer button at the top-right corner appears dull green. This indicates that the window is active. The Designer window has four panes:-
1-Palette:- This pane contains the components necessary for a graphical user interface design. It contains options such as User Interface, Layout, Media, Drawing and Animation, and so on.
2-Viewer:- This pane displays the appearance of the application.
3-Components:- This pane lists the components placed on the app screen. It shows a hierarchical view of the components.
4-Properties:- This pane shows various properties of the selected component. These properties are used to change the settings of the selected component.
Let us design an interface for Bouncing a Ball. For this, you need a ball and a canvas.
- Click on the Drawing and Animation tab in the left pane and drag and drop the Canvas on Screen1. Set Canvas Height and Width properties as Fill parent in the Properties pane.
- Now, select Ball from the same pane, and drag and drop it on the centre of the Canvas. Set some of the properties of the ball, for example, set Paint Color: Orange, Speed: 7, and Radius: 30.
- Click on the Media tab and drag and drop the Text To speech control on Screen1. The TextToSpeech control reads the given text aloud. It is an invisible component and cannot be seen on the screen like the ball.
Coding An App
Coding in MIT App Inventor is very similar to Scratch. To code your components, click on the Blocks button located on the top-right corner. You will switch into the coding window. Here, you can add your code.
For example, to change the background colour of your canvas, and hear the given text (“Bouncing Ball”) on initialisation of Screen1, add the following blocks:-
- Click on Screen1 in the left pane and add the Initialize event by dragging it on the Viewer area. The code inside this block will be executed when you start your app.
- Now, click on the TextToSpeech control in the left pane and add the Speak message block. This reads the given message. To add a message, click on Text in the Built-in category and add a Text string block. Add the text “Bouncing Ball” in the string.
- Now, click on Canvas1 in the left pane, and select the set Background Color to block to change the background colour. To set a colour, click on Colors
Running An App
When the design and code of your app is final, you need to test the app. You can set up live testing while you build apps using any of the following options
- With an Android device and WiFi Connection
- With a Chromebook
- Using the Emulator
- With an Android device and USB Cable