Android is an operating system for mobile devices like smartphones and a range of other mobile devices such as tablets, smart television and smart watches. The Android software package includes an operating system, middleware and key applications. It has also become common practice to refer to the devices using the android operating system as android device. Android programming is the process of creating applications for android devices. It involves using various programming languages, tools, and frameworks to design, develop, and test applications.

The history of Android development began in 2003 when Android Inc. was founded with the goal of creating an operating system for digital cameras. In 2004, the focus shifted to developing an operating system for smartphones. However, in 2005, Google Inc. acquired Android Inc. and the Android team decided to build the platform on Linux, an open-source operating system for personal computers.

Then on November 5, 2007, Google announced the formation of the Open Handset Alliance, a consortium of technology and mobile phone companies. This alliance included prominent members such as Intel Corporation, Motorola, Inc., NVIDIA Corporation, Texas Instruments Incorporated, LG Electronics Inc., Samsung Electronics, Sprint Nextel Corporation, and T-Mobile (Deutsche Telekom). The consortium was established to develop and promote Android as a free, open-source operating system that supports third-party applications and the rest is history.

Android-based devices leverage wireless networks to fully utilize features like one-touch Google searches, Google Docs (including word editors and spreadsheets), and Google Earth (satellite mapping software). Ever since the first version, the android has witnessed several version changes with android version 15 as the latest android version currently.

Programing languages
The first requirement for android programming is the programming language. I am sure you already know, right?🙂. The Java or Kotlin programming languages are used for android programming. Java was traditionally used for android application development. However, Kotlin is the official modern language. It is preferred for its modern features and interoperability with Java. Also, C++ is used for building native Android apps and games.

Development tools
The Android Studio is a very important tool in our android application development journey. The Android Studio is the official Integrated Development Environment (IDE) for Android app development. An IDE is a software that enables programmers to create other applications efficiently. While the android studio is the official IDE, there are other alternative IDEs for android development like Eclipse. Gradle is a tool for managing dependencies and building Android projects.

Frameworks
We also need you to know about the Android SDK. An SDK, Software Development Kit, is a set of tools to build software for a particular platform. The Android SDK provides an API, Application Programming Interface, for developing Android apps. An API is a set of rules or protocols that enables software applications to communicate with each other. Also important to know is the Android NDK which allows developers to write native code for Android devices. The android NDK is a tool set that lets you implement parts of your app in native code using languages such as C and C++. For certain types of apps, this can help you reuse libraries written in those languages.

Most android applications will fall into one of these categories; foreground applications, background applications, intermittent applications, widgets and live wallpapers. So let’s get to know them better.

1. Foreground applications
Foreground applications are designed to be used actively by the user. These apps require user interaction and are useful only when visible on the screen. When the user switches to another app or the screen turns off, foreground apps are typically paused or suspended to save resources. A common example is a game, where the user actively engages with the interface, and the app runs at full performance.

2. Background applications
Background applications operate primarily in the background with minimal user interaction. These apps perform their tasks without requiring the user to keep the app open. They usually provide services that the user doesn't need to interact with continuously, like system utilities or services that automate tasks. Examples include; SMS auto responders, which respond to incoming messages based on predefined rules, often without user intervention and alarm clocks. Set alarms and manage time-related tasks in the background until they need to alert the user.

3. Intermittent applications
Intermittent applications are a hybrid of foreground and background apps. They have components that require user interaction and others that work in the background. These apps are versatile, offering a balance between active and passive usage. Some examples include; media players which allow users to interact with them to select and play media. However, they continue to run in the background while playing music or videos and email and news apps which allow users to interact with these apps to read or send emails or check the latest news, but the apps also sync data, download new content, or check for updates in the background.

4. Widgets and live wallpapers
These are special types of applications that exist primarily as home-screen widgets or live wallpapers. Unlike standard apps, they are designed to display information or provide functionality directly on the home screen without launching a separate app interface. Widgets provide quick access to app features or data (e.g., weather, clock, calendar events). Update periodically or based on user interaction while live wallpapers are animated or interactive backgrounds for the home screen. They react to user input or change based on data (e.g., weather conditions, time of day). They are often used for quick access or aesthetic enhancements.

Activities, services, broadcast receivers and content providers are the building blocks of android applications. These four components often work together to create a seamless user experience🙂.

1. Activities are the building blocks of an Android app’s user interface. Each activity represents a single screen with a user interface, where users can interact with the applications data and functionality. Activities are essential for navigating through an app, presenting information, and collecting user input. Activities go through a well-defined lifecycle of (created, started, resumed, paused, stopped and destroyed) which helps manage resources and user interactions. It handles user inputs like taps, swipes, and other gestures. Activities can start other activities, passing data between them, which is a common way to navigate through an app. To clearly illustrate what an activity is, for instance in a social media application, different activities might include a login screen, a feed of posts, a profile page, and a settings screen.

2. Services are components that run in the background to perform long-running operations or to perform work for remote processes. Unlike activities, services do not have a user interface. They are ideal for tasks that need to continue running even when the user is not interacting with the app. Services can handle tasks such as playing music, downloading files, syncing data with a server, or running a timer (background processing). Services have their own lifecycle which is managed by the system and includes methods like onStartCommand(), onBind(), and onDestroy(). Services are grouped into two main types; started and bound services. Started services are initiated by calling startService() and can run indefinitely, typically stopping themselves when their work is done. Bound services allow components to bind to them and communicate. It is typically used for client-server interfaces within the app. A music player app which uses a service to play music in the background, allowing users to continue listening even when they switch to other apps.

3. Broadcast receivers are components that respond to broadcast messages from other applications or the system itself. These broadcasts can announce events like the battery being low, a new text message arriving, or a change in network connectivity. Broadcast receivers enable apps to respond to these events even when the app is not running. As a key feature, broadcast receivers react to system-wide or app-specific events, allowing the app to perform specific actions in response. They do not display a user interface (no UI) but can start an activity or a service to perform more complex operations. Broadcast receivers can be registered dynamically in code or statically in the app's manifest file; hence they can be dynamic or static. An SMS app might use a broadcast receiver to detect incoming messages and notify the user.

4. Content providers are components that manage shared app data. It is typically stored in a structured form like a database or a file system. They provide a standardized interface to access and modify this data, making it possible for different applications to share data securely and efficiently. Content providers offer CRUD (Create, Read, Update, Delete) operations for managing app data. They facilitate sharing data between different apps while maintaining data security through permissions. Data in content providers is accessed via URIs, which provide a uniform way to address different types of data. The contacts app on Android uses a content provider to allow other apps to access contact information. An email app might use this to let users select email recipients from their contacts.

Activities can start services to perform background tasks or use content providers to display data to the user. Broadcast receivers can trigger an activity to display a notification or start a service to handle a background task. Content providers enable data sharing between apps, while activities and services use them to access or modify data.

To effectively develop Android apps, you need a basic understanding of;
1. Java or Kotlin Programming Languages
2. Android SDK.
3. Components of an Android App such as Activities (UI screens), Services (background tasks), Broadcast Receivers (system-wide events), and Content Providers (data sharing).
4. User Interface (UI) Design:
Android provides a variety of UI elements (widgets) like buttons, text fields, and layouts (LinearLayout, RelativeLayout) for designing your app's interface.
5. Resources and Manifest File:
Android apps use resources like images, strings, and layouts stored in the res directory. The AndroidManifest.xml file describes essential information about your app, like permissions and activities. These are the basics of android programming

Android is the largest operating system for mobile devices with lots of opportunities for a fulfilling career. We have given you the basics of android programming to make your journey easier. Hire us when you need a helping hand; we can help bring your idea to life today!