Computer ApplicationsICSE Class 8 · App Development

Web and Mobile Apps and the Steps to Develop an App: ICSE Class 8

Updated 17 October 2026 · Fact-checked

An app has a user interface, logic and data, and runs in response to events. A web (online) app runs in a browser with nothing installed; a mobile app is installed from an app store and can use device features. An app is developed in five steps: plan, design the interface, program the logic, test, then build and share.

Follow the five steps in order, and remember that feedback after sharing sends you back to improve the app.

Illustration drawn for QuestionBuddy.

Understand What an App Is, Web and Mobile Apps, and Steps to Develop an App

Three parts of an app.

User interface (front end): screens, buttons, text boxes, images.
Logic: the instructions that run when you tap, type or swipe. Apps are event-driven: they wait for an event and then run its code.
Data: kept on the device (settings, photos) or on a server in the cloud (messages).

How an online app works. You tap a button; the app sends a request over the internet to a server; the server sends back a response; the app shows the result.

Web app versus mobile app.

	Web (online) app	Mobile app
Runs	inside a browser	directly on the device
Installation	none	from an app store
Internet	needed	many work offline
Camera, GPS	limited	full, with permission
Updates	on the server	user downloads
Works on	any device with a browser	the platform it was built for

Steps to develop an app.
1. Idea and planning: the problem, the users, the inputs, processing and outputs.
2. Design the interface: sketch screens.
3. Program the logic for each event.
4. Test, including wrong inputs such as blanks and letters; fix errors (debugging).
5. Build and share; collect feedback and update.
These mirror the algorithm steps: understand, plan, write, test.

Safe use. Install only from official stores; check permissions (a torch app does not need contacts); use strong PINs and never share OTPs; limit screen time.

App versus program. Every app is a program, but "app" usually means a focused, easy-to-use program for one task.

What an App Is, Web and Mobile Apps, and Steps to Develop an App: key facts

Parts of an app: User interface
Logic
Data; Events connect the interface to the logic.
Steps to develop an app: Plan
Design interface
Program logic
Test
Build and share; Testing includes wrong inputs.
Web app versus mobile app: Web browser, no install
Mobile installed, device features
Web server updates
Mobile user updates; Many services offer both.

Web	browser, no install
Mobile	installed, device features
Web	server updates
Mobile	user updates

How to answer What an App Is, Web and Mobile Apps, and Steps to Develop an App questions

Use this for comparison and steps questions.

1Name the two things being compared.
2Compare on the same points: where it runs, installation, internet, device features, updates.
3Give one example of each.
4For steps, write them in order and add one line of what happens in each.
5Link to safety if the question mentions permissions or downloads.

What an App Is, Web and Mobile Apps, and Steps to Develop an App in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

A hypothetical canteen app

Suppose a school wants an app for ordering lunch ahead of the break. Parents use many different phones; the school wants no installation.

Should the school build a web app or a mobile app, and why?

Try it first, then show the solutionSolution

Many different phones means one version should run everywhere.
No installation is wanted.
A web app runs in any browser.
Updates are made once on the server.

Answer: A web app suits the need: it needs no installation and works on any device with a browser.

Memory hook: Browser means web, store means mobile.

Tricks to remember What an App Is, Web and Mobile Apps, and Steps to Develop an App

Short memory aids. Say each one aloud once, then use it on a question the same day.

I-L-D
Interface, Logic, Data.
Use it when: Parts of an app.
P-D-P-T-B
Plan, Design, Program, Test, Build.
Use it when: Steps to develop an app.

What an App Is, Web and Mobile Apps, and Steps to Develop an App: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Where does a web app run? · 1 mark · MCQBoard level

Where does a web (online) app run?
(a) Only on the phone it was installed on (b) Inside a web browser (c) Only without internet (d) Only on a printer

Try it first, then show the solutionSolution

Web apps are opened by visiting an address.
They need no installation.

Answer: (b) Inside a web browser.

Example 2: Three parts of an app · 3 marks · Short answerBoard level

Name the three parts that work together in an app and give one example of each. (3 marks)

Try it first, then show the solutionSolution

Interface: a button (1).
Logic: code that runs when the button is tapped (1).
Data: saved settings or messages on a server (1).

Answer: User interface (a button or text box), logic (instructions run on an event) and data (settings, photos or messages stored on the device or a server).

Example 3: Request and response · 4 marks · Long answerHarder board level

Describe in order what happens when a weather app is used to check the weather. (4 marks)

Try it first, then show the solutionSolution

You tap Check weather (1).
The app sends a request over the internet to a server (1).
The server finds the data and sends a response (1).
The app shows the result on the screen (1).

Answer: The user taps the button, the app sends a request to a server, the server sends back a response with the data, and the app displays the weather.

Example 4: Browser map versus installed map · 4 marks · Long answerHarder board level

A map opened in a browser tab and a navigation app installed on a phone both show routes. Compare them on four points. (4 marks)

Try it first, then show the solutionSolution

Where it runs (1).
Installation (1).
Use of GPS or device features (1).
Updates or internet need (1).

Answer: The browser map runs inside a browser and needs no installation, while the navigation app is installed from an app store and runs on the device. The installed app can use GPS and other device features fully (with permission), while the browser version has limited access. The browser map is updated on the server, while the installed app is updated by the user, and many installed apps can work partly offline.

Example 5: Why test with wrong inputs? · 4 marks · Long answerHOTS / competency

A student tests a calculator app only with correct numbers. Explain what could go wrong later and what other tests are needed. (4 marks)

Try it first, then show the solutionSolution

Real users may leave boxes blank or type letters (1).
The app may crash or give a wrong answer (1).
Test blank boxes, letters and unusually large values (1).
Fix the errors found, which is debugging (1).

Answer: Real users make mistakes such as leaving a box blank or typing letters, and an untested app may crash or show wrong results. The student should test blank inputs, letters and very large numbers, then debug whatever fails.

Where students lose marks in What an App Is, Web and Mobile Apps, and Steps to Develop an App

The slips examiners see most often, and what to write instead.

Mistake: Saying web apps need installation
Web apps run in a browser.
Wrong working
A web app is installed from a store.
Right working
A web app is opened in a browser; a mobile app is installed.
Do this: Link web to browser.
Usually costs: 1 mark
Mistake: Listing steps in the wrong order
Testing comes before sharing.
Wrong working
Plan, program, share, test.
Right working
Plan, design, program, test, build and share.
Do this: Remember P-D-P-T-B.
Usually costs: 1 to 2 marks
Mistake: Accepting every permission
Over-permission risks privacy.
Wrong working
A torch app is given contacts.
Right working
Give only the permissions an app needs.
Do this: Ask what the app really needs.
Usually costs: 1 mark

Exam tips

Use a two-column comparison for web versus mobile and give examples.
Write the app development steps in order and link them to algorithm steps.
Mention permissions and official stores in any safety answer.
Keep examples everyday: messaging, maps, payments.

Practice questions on What an App Is, Web and Mobile Apps, and Steps to Develop an App

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
Which app type needs to be installed from an app store?
(a) Web app (b) Mobile app (c) Both always (d) Neither
Hint
Store means installed.
Answer
(b) Mobile app.
Q2 · 3 marks · Short answerBoard level
List the five steps of developing an app in order. (3 marks)
Hint
Plan first, share last.
Answer
Idea and planning; design the user interface; program the logic; test and debug; build and share the app.
Q3 · 3 marks · Short answerHarder board level
State two precautions to take before installing a new app, and explain why a one-time password must never be shared. (3 marks)
Hint
Official store, permissions, PIN.
Answer
Install only from an official app store and check that the permissions asked are really needed by the app. A one-time password gives access to an account or payment, so anyone who knows it can misuse it.
Q4 · 4 marks · Long answerHarder board level
Explain why the same service may offer both a web app and a mobile app. (4 marks)
Hint
Think about different users.
Answer
A web app lets anyone use the service in a browser without installing anything, and updates reach everyone at once. A mobile app gives better use of the camera, GPS and offline working. Offering both reaches more users on more devices.
Q5 · 4 marks · Long answerHOTS / competency
A school wants an attendance app for teachers on a hill campus with poor internet. Argue whether a web app or a mobile app is the better choice. (4 marks)
Hint
Offline working matters.
Answer
A mobile app is the better choice because many mobile apps can work offline or partly offline and sync when the internet returns, whereas a web app needs a connection. The cost is that each teacher must install and update it. If the connection were reliable a web app would be simpler to maintain.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.What are the three parts of an app?Show answer
User interface, logic and data.
2.What is an event?Show answer
Something that happens, such as a tap, that makes the app run code.
3.Where do mobile apps come from?Show answer
An app store.
4.Does a web app need installation?Show answer
No.
5.What is debugging?Show answer
Finding and fixing errors.
6.Name one safe-use rule for apps.Show answer
Never share OTPs.

What an App Is, Web and Mobile Apps, and Steps to Develop an App: frequently asked questions

Is an app the same as a program?

Every app is a program; the word app usually means a focused program for one task.

What is a hybrid app?

One built with web technology but installed like a mobile app.

Do all mobile apps work offline?

Many work offline fully or partly, but not all.