16. December 2016

Navilo’s Sudoku revolutionizes UI and UX… in three languages!

Download it now on the App Store!

App Store




The main novelties: a circular keyboard and a clean and elegant design

Sometimes, the best ideas are born in a very empty moment, when your head is the clearest and in this case, at Navilo, it was kinda like that with our incredible SUDOKU.

Here “Incredible” is not a randomly chosen word, its the definition of how we approached a world known games classic, nowadays even available on smartphones, in order to make it different.

And now you’re probably asking…What is making it so special?

First, the care we have put in – like raising our own child and therefore our most personal project. Because of that we took care of every one of the last details: the code, the user experience, the design… Everything new and most important, it’s ours.

Every one of us has put a piece into it and as everything in life, including developing an app, it has its own process.

The concept

One day, some years ago, our CEO was on a train and deeply lost playing the game SUDOKU when, suddenly, he realized that he had just finished the last of the limited number of Sudokus within his Brain Training game. Argh! What?! Just like that? Here and now?!

So, without wasting a minute, he started programming an entire library in C++ and QT for Windows, that would generate infinite SUDOKUS. To make sure that this wouldn’t happen to him again!



Three years later, while a few students were doing an internship at Navilo, the passionate SUDOKU addict would dust off the code and asked the students to adjust the code again, so they could reutilize it for iOS and Android and they did it! They used C++ and NDK on Android and Swift 3,0 on iOS.

So, why using C++ for the logic of the game? It’s a language specialized for the implementation on operative systems, because of its efficiency and the high value of its coding. What is making it an excellent partner to develop apps. Furthermore, it allows you to use the same library on both platforms and reduces the amount of changes within the work itself.

Once we´ve reached that point and after validating the code, as an approved concept, we decided to give it a body.

First steps

First, we checked the existing competitors for their SWOTS (Strengths, Weaknesses, Opportunities and Threats).

Because right from the start, one of the most important things for us was to change the whole user experience. We wanted to achieve, that the functionality and the design directly reflects Navilo as a Company: A workspace where even the hardest things become easy, even when they seemed to be impossible in the start.Everything is a matter of time and dedication, so we sat down to set the base of interaction and flow.

It ended up in two main points:

1. Settling the idea, which came out of the past, over a circular keyboard, which shows up centered around each number square and not at the end of the screen. Our intention was to introduce a new form of choosing or drafting the numbers, because the most common keyboard systems in Sudoku Apps are inefficient and poorly original.

2.Regarding the design, we wanted it to be clean, subtle and elegant. A light and nice one, perfect to disconnect yourself from the non-pleasant reality of life – another renewed aspect of ours in comparison to the rest of the existing Sudoku’s. We didn’t want to be as poor and chaotic as all the others, but nothing less than simple, smarter and good looking.

We found a Designer that could take the essence of our idea and turn it into mesmerizing design.

Layered over a blurry background, in soft colors, you will find clear and simple texts, minimalistic icons and lines in white and a very intuitive and comfortable handling. A simple click on the numbers box is showing a circular keyboard where you barely have to move your finger to do everything you want.

The result was simply amazing and so much more attractive over the others. Would you agree, wouldn’t you?

2 and 2 are 4 or rather 22?

Next step: The Code.

Because of the single library, we simultaneously started designing on both platforms. But very soon we realized that it had become inefficient, because a lately detected mistake would have meant double work time in the end.

So, finally, we decided to follow the LEAN SPIRIT (Lean thinking is a business methodology that aims to provide a new way to think about how to organize human activities to deliver more benefits to society and value to individuals while eliminating waste.) to get the Minimum Viable Product: the iOS App.

Following the method of agile development (Scrum) we had to sit down again. The changing character of the project made it excellently suitable for our already existing agile method of internal work. We set the goals straight and determined the issues (Product Backlog) and divided them into Sprints.

What is a Sprint? For the ones who doubt, there is no actual lion running behind you to hunt you down…. It’s a group of requirements and tasks from the backlog which need to be executed in quite a short amount of time and it allows all the people participating in the project to follow the status of everyone’s work, including their own, and to detect problems and offer solutions straight away.




The iterative phases of creation and validation follow one another in a process of progressive development or in crescendo by means of the definition of new sprints with changes and implementations on the previous ones, until the complete execution of the project.

The final move

Once everything is almost finished…the nightmare of every professional developer starts: The Testing.

You`ve thought everything was set and done, the project was finally finished and simply perfect but naaaaaaahhhh! You´re wrong! 
As soon as the testers started reviewing, it became quite evident, that everything we thought was under control, clearly wasn’t!

“This Icon doesn’t work, that text is hard to read.”

So, we:

“Bah! Just a couple of changes and its fixed.”

But what about…?:

*You click* and nothing happens.

“The Sudoku I solved on Tuesday, without any hint and in record time, isn’t showing in the History!”


“Ok, fine…..A couple of changes more and then it’s done!”

Final evaluation

As always when we finish a project, we do an evaluation of results. Many sprints have followed other sprints. Lots of coffee and laughter about whether the SUDOKU lines are too thin or if there’s someone blind. But much greater has been the satisfaction of having created a product so well finished and with the best partners. In addition, we have been faithful to our philosophy of work and to the SUDOKU itself, because, for those who do not know, SUDOKU means in Japanese: “The numbers must stand alone”.

And every number, indeed, has its space and fulfills its role. And in its row, its column and its quadrant, is unique and indispensable to find the solution. Like every one of us within the team! But … What would happen to Navilo (or SUDOKU) if any of the elements were repeated …? Or did not do what they were meant to do?

Eeeeeek! Wrong answer.

Because at Navilo we know we have to work in harmony in order to be successful together.How great it feels to occupy your place, fulfilling your function, while being in good company!

Life already has its way to challenge us constantly … So, we at Navilo, recommend you to do as we do: Learn to work playful!