From J2ME to KaiOS with Valeriy Skachko

Posted by Tom Barrasso on

About Valeriy Skachko

Valeriy Skachko is one of KaiOS’ top certified developers. Since 2018, he has published over 100 KaiOS apps, available on both the KaiStore and JioStore. Learn about his journey and lessons you can apply to your own software development.

How did you get started with KaiOS?

I started developing the first applications for mobile phones, at that time in Java ME (J2ME), in 2012, in addition to my teaching activities. I needed to give the students a new topic - and I decided to offer them the development of an application for mobile devices based on Java ME. After that, I became interested in developing applications; there were many projects on Android and iOS, but my favorites were still feature phones. It was very interesting to create applications that could work with minimal system requirements and a small screen. It was a challenge for me. Later, in 2018, I learned about KaiOS and immediately fell in love with this system. Since then, I have been mainly programming for KaiOS.

What technologies do you use for KaiOS development?

If possible, I try not to use any frameworks. I want to see every line of my code and know why it is needed. Well, and if something happens, all responsibility for errors in the code is also mine. I use Notepad++ as an IDE, it is very convenient and concise.

Valeriy Skachko’s 100+ KaiOS Apps
Valeriy Skachko's 100+ KaiOS Apps

What is your favorite KaiOS app that you developed?

At the moment, I have developed and published more than 100 apps on the KaiStore. I roughly calculated that I created 2 apps per month for 5 years. Since programming for me is more about the desire to do something new, I try to make my apps different from each other. One game, although not very popular, was a real challenge for me - Dino Virtual Pet. Even as a child, I had a toy - a Tamagotchi - with a dinosaur. I wanted to make not just a game like this on KaiOS, but to make it as similar as possible. To do this, I searched all over the Internet for images of the toy, videos of gameplay, etc. Then, over a month, I gradually restored all the animation, movements, and growth of the pet.

How do you pick what app to build next?

First of all, I analyze what’s missing in the KaiStore. Then, I study the trends of what is popular among queries on the Internet, what apps are most often searched for. I also analyze popular apps for Android and iOS. My daughter also suggested some app ideas to me - she uses a KaiOS Sigma Mobile X-Style S3500 sKai phone.

What advice would you give to a new KaiOS developer?

My advice is to take the development of any application, even the simplest one, seriously. Spend a little time optimizing the code, testing the application, and making sure it looks and works well. Unfortunately, there are a lot of low-quality applications in the KaiStore. Many developers do not spend time on optimization and use heavy frameworks, which causes applications to slow down and perform poorly.

This gives many KaiOS users the impression that the system is bad - when in fact this impression is created by low-quality applications. Although, it’s nice that there are also quite a lot of high-quality programs: an app for listening to podcasts - PodLP, nice 3D apps - Space Walk 3D and AirshipCombat3D by Christian Waadt, high-quality games - Word Starz by Playerthree and Lanterns by Curioso.

Also a piece of advice - be sure to buy a KaiOS device - you won’t be able to fully test applications without a real device. At the initial stages, try to figure it out yourself - there is already enough documentation on the Internet. If the problem is not solvable for you, join groups on Discord and Reddit - there are many programmers there who can help you.

Is there anything you would do differently?

The first thing I would probably do is not violate the rules for publishing advertising in Android applications, for which I was banned from Google Play many years ago. But otherwise, I probably agree with Tallulah Bankhead’s quote:

If I had to live my life again, I’d make the same mistakes, only sooner.

What’s your favorite KaiOS phone?

I have two favorite devices based on KaiOS. Firstly, this is MTN Smart. This was my first KaiOS device and it had 256 MB of RAM. I use it very actively to test applications, even now. If any application works on it, then it will work 99% on any other device.

The second device is the Nokia 2780 Flip - this device runs on KaiOS 3.1 and you can see the speed contrast between versions 2.5.x and 3.x - everything runs much faster and smoother.

What achievements are you most proud of?

I am very pleased to know that I was at the origin of the formation of KaiOS. I was the first third-party developer whose applications were published in KaiStore. I was also the first third-party developer to test KaiAds advertising, and, accordingly, the first to integrate it into my applications. Also, during the first two years, I developed the largest number of applications for KaiStore. Now I don’t stand out with the number of applications, but I hope their quality inspires trust among users.

I am also very proud of my collaboration and development of KaiOS projects with campaigns such as Justdiggit (a greening program for Tanzania), Avert (a sex education program for Nigeria), and Robert & John Limited (education and curriculum for children in Nigeria).

Where can we learn more about your work?

I regularly update information on my website - - there you can see all the programs and outsourcing projects I have developed, as well as ways to contact me. I also regularly post news regarding KaiOS on my Twitter/X - @valeriy_skachko. You can watch video reviews of some of my programs on my YouTube channel - @valesk.

This case study was provided by Valeriy Skachko without compensation. Valeriy is the first third-party developer to publish on the KaiStore, and one of the first independent developers to publish on the JioStore. He’s developed over 100 applications in 5 years, notably including a Period Tracker and the BeSafe COVID awareness app.

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