Kotlin App Examples – 6 Amazing Apps Built With Kotlin Language

Key Takeaways

• Well-established companies like Pinterest, Evernote, Netflix, Uber, Duolingo, and Coursera have successfully integrated Kotlin into their Android app development process, proving its reliability and effectiveness.
• The increasing number of successful apps built with Kotlin reflects the language’s growing popularity and solidifies its position as a top choice for Android app development.

Despite having billions of users, have you ever experienced downtime while using Netflix?

While booking a ride from Uber, have you ever faced an error?

Your answer will be most probably NO.

Because, these companies have taken the smart decision and switched to Kotlin programming language to make their mobile app efficient, scalable, and error-free.

But, what are the benefits of moving your app solution to the Kotlin programming language?

This blog covers the top Kotlin app examples, along with the challenges they were facing and how Kotlin helped them to solve those challenges successfully.

Top Kotlin App Examples

The table below contains the top companies that have implemented Kotlin to build their Android applications. Even, to understand how to develop an Android app using Kotlin, this guide will help.

Refer to this table to know the revenue, ratings, and download option to check how they have built their app.

Apps	Revenue (2021)	Ratings (Play Store)	Download Link
Netflix	$7709 Million	4.5 (12,642,411)
Uber	$4.8 billion	3.9 (94,55,581)
Pinterest	$847 million	4.6 (8,777,988)
Evernote	$50 million	4 (16,69,532)
Duolingo	$45.3 million	4.5 (11,939,405)
Coursera	$109.9 million	4.2 (130,143)

In the next section, we will focus on two points:

1. Netflix



Image Source: Netflix

Have you ever wondered how Netflix mange to handle billions of users every day? Why does their application never crash? As of March 2020, Netflix has over 50,000 titles included and 5817 series are there in Netflix. Still, you will not experience a single issue while streaming content on Netflix.

If we discuss the Netflix app, Kotlin has a simple syntax that boosts the efficiency and speed of Kotlin app developers. It follows a strict pattern. It now takes fewer lines and less time to write an application. Many people admire Kotlin for its quality, brevity, and readability, which has helped it to outperform Java.

What Challenges Netflix Was Facing Before Using Kotlin?

• The app used crashes sometimes due to an excessive amount of users.
• The application used to lag after a while.
• The app size of Netflix was larger than usual.

How Does Kotlin Help Netflix?

• Netflix wanted to use a multi-platform approach, and the agnostic code for Android and iOS is possible to write in Kotlin and then used for both systems at once.
• Netflix app development is the result of the Android Kotlin library, and on the other, as a native universal framework for iOS. The latter is accomplished with the help of Kotlin-native, which allows code to be translated natively for iOS rather than running in the Java Virtual Machine.

2. Uber



Image Source: Uber

Uber is one of the most well-known for its taxi and food delivery services. Uber has switched completely to Kotlin development for mobile app development. The reason behind that is, they have heavily invested in Kotlin app development for internal tooling procedures like annotation processors and Gradle plugins.

What Challenges Uber Was Facing?

• Internal tools were not working properly, even the model management.
• Initially, the performance of Uber was lagging behind before applying Kotlin.
• Users were facing errors and lag while booking rides and while paying for the services.

How Does Kotlin Help Uber?

• Uber currently heavily relies on Kotlin to help allow their users to utilise their Internal tool.
• The Kotlin programming language’s focus is thread safety, context, and data sharing between threads. There is no requirement to use special annotations, as there is a priority thread safety, context, and data sharing.
• The Kotlin is open for all the developers and the implementation is without any cost.
• The source code of Kotlin makes it simple to locate and report a problem in the event that one arises so that the language’s creators are aware of it.

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3. Pinterest



Image Source: Pinterest

Pinterest is a well-known photo-sharing mobile app that was initially built in Android. The company was founded in 2010, after which it migrated from Java to Kotlin 2016. The prime reason was the robustness of the Kotlin language. Apart from this, Pinterest has implemented Kotlin even before Google announced its first-class support.

What Challenges Pinterest Was Facing?

• Java was considered the primary language for custom Android application development. By the time, the Pinterest team was searching for a productive, concise, modern, and alternative boilerplateless alternative.
• Developers need to spend more hours building and testing the product.

How Does Kotlin Help Pinterest?

• Kotlin allows a developer to code with speed and confidence and removes much of the rote work that had been required while using Java.
• The application’s user experience, as well as its usability, has been increased significantly.
• Pinterest is well-known around the world and has been around for quite some time. Because of the functionality and convenience of use, their Android application is used more than their website.

Check the case study of two popular mobile applications we have built using Kotlin programming language.



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4. Evernote



Image Source: Evernote

Evernote is a note-taking app that was initially developed using Java, before moving to Kotlin. Evernote’s Android app now includes Kotlin support. The blog of Evernote includes only slight information about the tech specifications related to Kotlin integration The company realised soon, that moving to Kotlin can be the wise choice when it comes to their development stack.

What Challenges Evernote Was Facing?

• Users were facing an increasing amount of app startup time.
• Data sync was the major issue, faced by the majority of the users. After adding a note, sometimes the app was not synching that information in real-time.
• The crashing issues were the major turn-off for the app’s success, as it used to crash often because it was not able to handle.

How Does Kotlin Help Evernote?

• Evernote’s Android app employs the Kotlin programming language for reliability, clarity, and performance. Evernote is a well-known program that is specifically intended for taking notes and managing tasks.
• Evernote has added functionality such as scanning handwritten notes, web pages, images, to-do lists, audio, and more thanks to useful Kotlin’s features.

5. Duolingo



Image Source: Duolingo

With over 42 million users in 2020, Duolingo is a well-known language learning platform. Even, it comes in the category of the most downloaded education app across the globe. The primary goal of the company is to make education without any charge accessible to everyone. The gamification feature makes the Duolingo interactive app that helps users to learn complex things in a simple way. Refer to this guide, if you want to know more about how to create a language learning app like Duolingo.

Being a primary platform Duolingo has developed the Duolingo English Test, which is a convenient and affordable language certification you can sign up for. Even institutes such as the University of North Alabama, Arizona State University, and the University of Arkansas in the USA accept the Duolingo proficiency test.

What Challenges Duolingo Was Facing?

• The lines of code were increasing by 46% every year for Duolingo. To solve this issue, it was essential to migrate the code from Java to Kotlin.

How Does Kotlin Help Duolingo?

• Duolingo’s developers found that by changing the codebase to Kotlin, they reduced the line count by 30% on average, and up to 90% in some cases.
• Kotlin is significantly less verbose than Java, making it faster and easier to write and maintain. Its seamless Java interoperability and cautious approach to adding new language features make it simple to learn for any Android developer.

Want to Develop Your Android App using Kotlin?

Our Kotlin consultant will guide and assist you in developing scalable Android app solutions for your company.

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6. Coursera



Image Source: Coursera

Coursera is a non-profit educational organization that offers free online courses taught by renowned colleges and institutes such as Stanford and Yale. The prime reason for choosing Kotlin is Coursera does not have distinct platforms for Android and iOS.

For offering extremely dynamic features and a flawless experience to their audience, the popular MOOC (massive open online courses) relies in part on this Android application development language.

What Challenges Coursera Was Facing?

• For Android developers, finding minor bugs was difficult prior to use Kotlin.
• The attempt to access null values is a typical problem in many programming languages. As a result, an error occurs.

How Does Kotlin Help Coursera?

• Kotlin has completely eliminated errors that were causing issues in the Coursera app, that is the core reason why Coursera works flawlessly without any issue.
• Kotlin provided this app with a smooth interface and all the necessary features to keep improving the application.
• The main reason behind the flawless working of Coursera is Kotlin, as it removes errors from your code permits the app to work smoothly.

So, now you have learned about various apps built with Kotlin. But are you confused about choosing  Java or Kotlin for creating android apps?

To dispel such doubts, we’ve created a PDF with 5 reasons why Kotlin should be preferred over Java for Android app development. Download the PDF below to learn more about these reasons.

5 Reasons

Why Kotlin is Better than Java for Android App Development

Download Free Guide

Here are FAQs about the Kotlin programming language to help you know more about the language.

Let’s Build a Successful Kotlin Application Together

In this blog, we have discussed the top companies who have migrated towards the Kotlin programming language to scale their application. If you want to build a sustainable business over the long run, make the smart choice and build your mobile app using Kotlin.

As Kotlin has already been adopted by major corporations in their Android applications. There are also open-source projects that are well-liked by developers, demonstrating that the language can be successfully used in Android development.

If you are planning to signup for an Android app development service, you should consider Kotlin as your primary mobile app development language. We have a dedicated team of Kotlin app developers who will help you turn your idea into a fully-fledged mobile app. Contact us to build your customized Kotlin app.