I still remember the day a few years back when I started Android development and stepped into this vast, mysterious world, with almost no idea where to start and what to do next.

Searching on Google, stumbling upon miscellaneous articles, and checking out StackOverflow answers were the only ways for me to gather knowledge on Android. Back then, I had a hard time finding good-quality tutorials to learn from, but with time I started to figure out the places where I could find the most useful resources to gather knowledge and improve my skills.

To help out other Android developers like me, I've gathered a comprehensive list of resources that nearly all Android developers should find useful, whether beginners or seasoned professionals.

For beginners

These are invaluable for any Java programmers starting their Android development journey.

An easy and beginner-friendly course developed by Google to learn the basics and fundamental concepts of Android development quickly.

A simple, easy, and complete guide for all beginner-level Android developers who want to develop their first Android app using the de facto open-source IDE, Android Studio.

This is one of the most underrated resources, one that almost all Android developers should know about right from the start of their development journey.

If you are just stepping into the vast world of Android development, then it's likely that you will get overwhelmed with a lot of new concepts and terms. Don’t worry; Google has designed an interactive, easy-to-use glossary, with code examples, to make your life a lot easier.

The official training guide for Android developers from Google is extremely useful for any beginner developer. The training covers the basics, with plenty of code examples.

A very insightful and resource-filled article for novice Android developers. Always learn from others' experiences and mistakes, and never repeat them yourself.

Not familiar with XML? Now's the time to learn it, as you will need to use it heavily to design your layouts in Android. It is very easy and shouldn't take much time to grasp.

If you are going to communicate with web services and make API calls from your Android app, then it is very important for you to have a good understanding of HTTP and REST.

For the experienced developers

If you've been doing Android development for a year or two, here are some advanced resources that will take your knowledge of Android development even further.

A well-designed course by Google that is perfect for intermediate-level Android developers.

If you are struggling to find elegant ways to solve critical software development problems in Android, these common design patterns can help you a lot.

The best way to get better as a developer is to read great code. Android has a very rich community of open-source apps, but how do you know which ones will teach you the right lessons? Don’t worry; this article has you covered.

Learn how to choose the right architecture for your complex Android app, one that enables better development, testing, debugging, and maintenance.

We all know how complex and frustrating Android’s Activity and Fragment lifecycle can sometimes get, but there are other, more modern ways of creating apps as well. This article can show you these modern Android development methods.

Jump into the world of reactive programming on Android with this easy crash course.

Get an in-depth look into the Android View constructors, how they work, and how you can get the most out of using them in your own custom views.

If you want to understand how the asynchronous core of Android framework is built and how to leverage that knowledge to make smooth, fast, and high-quality applications, this is exactly what you need to look at.

An in-depth tutorial on how Views and ViewGroups work in Android and how you can create your own custom UI components.

Not many developers properly understand how the different launch modes in Android work. This tutorial teaches you how to leverage those modes to create excellent navigation in your app.

If you have been using open-source libraries in your Android apps a while and now you'd like to give some contributions back to the community, here is a complete, in-depth guide for publishing your own library.

Learn how to have a smooth and successful Android app launch in the Play Store.

This GitHub repository contains blueprints for learning about the different architectural tools and patterns to develop Android apps like a pro.

Android Instant apps are a new way to create greater engagement and provide native-like functionality through the web rather than an app on the homescreen. This article will explain the benefits and how easy it is to make an instant version of an existing app.

This article provides some options for your developer toolchain that could make you a lot more productive.

Even if you've been using Android Studio almost every day to develop your apps, you might not realize some of the really useful features hiding within.

Best practices in Android

Following best practices helps you to develop cleaner, better apps. This becomes even more important if you are developing with a team. You need best practices for maintaining a consistent development style that keeps everyone on the same page.

A resource-filled article explaining several aspects of Android development best practices.

This article teaches you the best practices for using strings.xml resource files.

One of the best and most complete resources explaining the best practices and guidelines for various aspects of Android development.

Want to use Android in your enterprise? Check out this article on Android for Work's best practices.

A quick and useful list of some more Android best practices.

Effective Java (by Joshua Block) is considered one of the best books for learning how to write high-quality, maintainable Java code. This post focuses on how you can make the best use of those techniques and principles specifically in Android development.

If you have chosen the reactive way for building Android apps, then these tips can help you avoid some common mistakes and get the best most out of this strategy.

An in-depth article about some of the common techniques for storing and securing secrets (passwords, API keys, and other sensitive information) in Android apps.

Designing beautiful apps

A clean and beautiful UI is what makes your app appealing and usable. Here are some resources for making sure your app has both style and substance.

A very well-written article giving you a close look at Google's Material Design techniques for Android.

Learn how you can create beautiful and meaningful animations in your Android app that will make it stand out from the rest.

The freshly baked ConstraintLayout completely changes the game when it comes to designing layouts for your Android apps. This article can help you understand the basics of ConstraintLayout so you can quickly start using it.

Design higher-quality apps by not making these common mistakes while embracing Material Design in your Android app.

A very insightful article giving you a more scientific perspective into Material Design and how you can leverage it to the fullest extend when designing your app.

Bonus resources

Some miscellaneous resources that you don't want to miss.

If you want to keep up with the latest developments in the Android community, make sure to follow these expert Android developers on Twitter.

Get Started with Android Things Today!

Want to dive into the world of IoT using Android tools? Here is a good resource for you to start your journey.

If you are interested in developing apps for Android wearables, this is a complete tutorial to get you started.

A very interesting article about the nitty-gritty details of the Android resources and attributes you probably didn’t know.

Want to develop apps for TVs or make your existing apps support this new platform? Here is a good quick introduction.

Useful sites

Want to stay updated on the latest development news, tutorials, and events in the Android world? Here are some of the best sources to check out.

Never miss out on the latest development news, articles, screencasts, and other events in the Android world. Android Weekly offers free newsletters every week for you to stay updated with no effort.

If you love listening to podcasts, then you will not want to miss the biweekly Fragmented Podcast, which covers various Android tools, patterns, and best practices with the help of high-profile guest developers.

One of the best and most up-to-date crowdsourced resources for Android developers. Here you'll find guides and tutorials about almost everything in Android. And the best part is that it is completely open source, so you can contribute to it as well.

Get high-quality, bite-sized Android development screencasts on a wide variety of development topics released every week.

This is the place where you will find essential information for designing the UI and UX of your app.

Mark Murphy, who is known for authoring the book The Busy Coder’s Guide to Android Development, has an excellent blog on Android development.

Created by Lars Vogel, this site has scores of in-depth tutorials on Java and Android development topics that can be invaluable for both beginners and intermediate-level Android developers.

A very active community of Android developers from all over the world discussing and sharing information on various Android development-related topics.

This is the official blog Google uses to communicate directly with the Android development community. All the latest development-related news and announcements appear here first before anywhere else.

I hope these resources will help you learn more about Android development and build better apps. If you found this useful, share it with your friends and co-workers as well. If there are any Android development resources that weren't included in this article that you find particularly useful, share them in the comments below and we will consider adding them to our evolving guide.

Image credit: Flickr

Keep learning