Mobile Application Development I SS2 Digital Technologies Lesson Note

What is a Mobile App?

Think back to 10 or 15 years ago. If you wanted to check the weather, play a game, or send a message, you usually needed a big desktop computer. Today, we carry all that power in our pockets.

A Mobile Application (or “App”) is a software program designed specifically to run on a mobile device, like a smartphone or a tablet. Unlike computer software, mobile apps are usually built to do one or two things really well (e.g., WhatsApp is for messaging, Uber is for transport).

The Two Big Bosses: Operating Systems (OS)

Just like a car needs an engine to run, a phone needs an Operating System to manage its hardware. In the mobile world, there are two main “Bosses”:

1. Android (owned by Google): Used by many brands like Samsung, Tecno, and Infinix. It is “Open Source,” meaning many companies can use it and change it.
2. iOS (owned by Apple): Used only on iPhones and iPads. It is “Closed,” meaning only Apple controls how it works.

Teacher’s Note: Because these two systems speak different “languages,” an app built for an Android phone won’t work on an iPhone unless the developer makes two different versions!

Three Ways to Build an App

When a developer wants to create an app, they have to decide how to build it. There are three main categories:

1. Native Apps (The Specialists)

These are built for one specific system using that system’s favorite language (e.g., Java or Kotlin for Android; Swift for iPhone).

• Pros: They are very fast and can use all the phone’s features easily (like the camera or GPS).
• Cons: You have to build it twice if you want it on both Android and iPhone.

1. Web Apps (The Pretenders)

These aren’t actually “installed” on your phone. They are websites that are designed to look like apps. You open them through a browser like Chrome or Safari.

• Pros: They work on any phone.
• Cons: They need the internet to work and can’t always use the phone’s special features (like the fingerprint scanner).

1. Hybrid Apps (The All-Rounders)

A mix of both. Developers write the code once, and it gets “wrapped” in a way that allows it to work on both Android and iPhone.

• Pros: Saves time and money.
• Cons: Sometimes a bit slower than Native apps.

How Do Apps Make Money?

If most apps on the Play Store are “Free,” how do the developers pay their bills?

• Advertisements: Showing small ads at the bottom of the screen.
• In-App Purchases: Charging for extra features (like buying “coins” in a game).
• Subscriptions: Charging a monthly fee (like Netflix or Spotify).
• Premium Apps: You pay a one-time fee to download it.

Summary Table: Mobile App Categories

The Life Cycle of an App

Before you see an app on your phone, it goes through these steps:

1. Idea: Deciding what problem the app will solve.
2. UI/UX Design: Drawing how the buttons and screens will look.
3. Development: Writing the actual code.
4. Testing: Checking for “bugs” or errors.
5. Launch: Putting it on the Google Play Store or Apple App Store.

Class Discussion / Review Questions

1. Look at your phone. Name three apps that you think are Native (they came with the phone and work perfectly offline).
2. If you were to build an app for your school, would you make it Native or Web-based? Give one reason why.
3. Activity: Draw a simple “Home Screen” for a new app that helps students keep track of their homework. Where would you put the buttons?