Android is by far the most popular operating system. In 2021, it has a market share of 72.84% across 1.6 billion users worldwide. It has retained its market share over the years as iOS ate up the market share of all other operating systems. Choosing Android is a good career choice, because companies are always looking for good Android developers.

But it's not easy being an Android developer. First, you need to understand the concepts of the operating system, like Activities, Services, Intents, etc. Second, Android lets you decide what type of architecture you'd like to use. Will you go for MVP, MVC, or MVMM? Not always an easy choice. Third, there are tens of thousands of wildly different devices that run Android. How do you make sure your app runs well on all those devices?

Thankfully, there are a few Android frameworks that will greatly streamline your app development process. That's what this blog post is about. It's a list of the 5 Android frameworks that will help build the bones of your Android app quickly and easily.

This list only includes the Android frameworks that still matter in 2021. There are many other frameworks that are either no longer maintained or widely panned by developers. Such frameworks are not on this list.

Android NDK

The Android Native Development Kit is a good extension for the developers who write native Android apps in Java or Kotlin. The NDK allows you to embed C or C++ code into your Android apps via the Java Native Interface (JNI).

While you won't use the NDK for your entire Android project, it's great for the parts of your application where performance really matters. You can build code with the NDK through the Make-based ndk-build script, CMake, or other build systems.

React Native

React Native is the first cross-platform framework on this list. Facebook used it internally for years before they open-sourced it in 2015. It quickly became the most popular app development framework. Today, React Native has close to 100,000 stars on GitHub and is used for all Facebook apps, as well as for apps from Tesla, Bloomberg, Uber, Walmart, and more.

React Native allows you to create native apps for both Android and iOS. It takes your React code and compiles it into native code and widgets that work on both operating systems, which you can then see on your device or on an emulator.

While React Native's list of components is fairly small in comparison to some of the other Android frameworks on this list, you can easily expand on them with custom rules (which you're quite likely to do). React Native is particularly great if you're already familiar with React and JavaScript.

Flutter

Flutter is the biggest success story on this list. When Google first released it in 2017, little did they know it would become the best-loved and most-used cross-platform app development framework in less than five years. Today, Flutter is used by BMW, eBay, Square, Alibaba, and many others.

Flutter has its own language called Dart, which is a relatively easy language to pick up, and a comprehensive suite of widgets for both Android and iOS. While these widgets are based on Material Design guidelines, they're also adaptive, meaning you can use them for both Android and iOS.

Flutter uses a high-performance rendering engine to draw its widgets instead of relying on web browser technology or the widgets that a particular device ships with. This means you can create the best UX without having to compromise because of platform constraints.

Xamarin

Okay, hear me out. Xamarin isn't the most-loved or most-used app development platform on this list. But its developer experience has greatly improved the years and Microsoft, which owns Xamarin, is betting big on it. Xamarin allows you to create native mobile apps on iOS and Android with .NET and C#.

You use Xamarin to write the backend code and the app's business logic. You can then use Xamarin.Forms to extend that code to the UI, because Forms is an abstraction of the underlying platform's UI components, exposing them in an easy-to-use markup language.

Microsoft is in the process of integrating Xamarin into .NET as a core workload. Additionally, Xamarin.Forms is evolving into .NET MAUI, which you can read about here. So Xamarin, while not nearly as popular as React Native or Flutter, certainly isn't dead. If you can program in .NET, it's well worth checking out.

Ionic

Ionic is a cross-platform, mobile UI toolkit first released in 2013. It has a large list of components that are highly customizable and adaptive. Ionic has great documentation that clearly shows how it integrates with React, Angular, Vue, and JavaScript.

Ionic is different from React Native, Flutter, and Xamarin because Ionic doesn't compile to native code. Instead, the app code is wrapped inside a WebView. You access a device's hardware features through a tool such as Capacitor. You can go for Ionic if you're familiar with creating web apps and don't have enough time to learn the intricacies of Flutter or React Native.

This was a list of the 5 Android frameworks that are relevant in 2021. If you write native Android code, check out Android NDK. If you want to write something cross-platform, go for either React Native or Flutter. Unless you prefer writing web code wrapped in WebView, then go for Ionic. Finally, if you're familiar with .NET, check out Xamarin.