Idea:

Originally, I wanted to try out a new feature of a game engine (a software library) to conveniently download data from a server. So, I programmed a quiz that downloads the image of the next question in the background. As the app grew, I searched for a unique game idea not yet in the app store. My lovely wife had the idea of creating culture questions for each country!

Code:

I took half a year off between two jobs to work on the programming. As a professional game programmer, this was a smooth and enjoyable task. However, when I integrated platform services like in-app purchases, advertisements, achievements, and leaderboards, Google released a new version of their code—with bugs. The old version was no longer supported, so I had extra work fixing those issues.

Graphics:

A more — let’s say, well-hidden — talent of mine is creating graphics. I bought user interface and character textures and added the characters as sprite animations, which worked well. The characters reacted humorously depending on whether the answer was right or wrong. That is, until I tested it for the first time on a slow Wi-Fi signal. Would you like to wait half a minute for each question? Probably not. So, sadly, I dropped the animations, and now it loads lightning-fast.

Questions:

The most common question I get is where all these questions come from. Honestly, I should have asked myself this before starting the project because it takes me a full day to write the questions for each country. The quiz databases I found online were disorganized, filled with dull, unsuitable questions. So, I assembled the questions myself by watching documentaries, browsing fun-fact websites, and researching culture, gestures, habits, official holidays, superstitions, and more. It was actually a lot of fun.

After that, I added an explanation text, a character, and two pictures (with proper copyright) for nearly every question, which also took a long time. In fact, most of this work happened during hundreds of train rides to and from work!

Once all that was done, I added text encryption to prevent theft.

Localization:

I wrote a ton of questions and encountered an unexpected problem: Google Sheets has a limit of 1,000,000 cells per document. Yes, a million! I had to reorganize the text imports... The day when my Google sheet took about half an hour loading with a fast internet connection made me reorganize the text imports again...

Luckily, I used automatic translation. Hiring human translators for 20 languages would have cost €100,000 — far too much for a hobby project. This put me in a dilemma: some users give bad ratings because their language is missing, others because their language is only machine translated. I spent several weeks translating German to English myself to improve quality.

Beta Test:

Besides family, finding testers was surprisingly hard—most friends just weren’t interested in a quiz game. I noticed that the average question was answered correctly only 30% of the time, instead of my estimated 70%, so I had to add even more questions to match my intended gameplay experience. I also added a setting to exclude the hardest questions. 

Release:

The days when you could set up and upload an app to the Google Play Store in one day are over. It took me several days just to study all the new policies and settings. Now, you first release the app to friends and family, then to a limited audience, then to open beta, and finally, and finally to everyone.

The most difficult tasks in app development are: What is the app about? What is the name of the app? Is it ready and can it be published now? Before release, after marketing started, I had to rename the app several times because apps with the same name were published. Renaming the app is about one week of work in total! In the first three months after my release, several apps were published with the same name, which I find quite inconsiderate. If you wonder about long, strange app names in the stores—it’s to include as many good keywords as possible.

After Release:

Half a year later, I can give an initial summary. At first, the app wasn't downloaded at all. Unfortunately, the search results for practically all search terms are already occupied by established apps and even paid results. I had to familiarize myself with app store optimization (ASO), and the numbers started to rise.

The app has been very well received, with nearly all of over 50 reviews giving it five stars! Unfortunately, there is one very angry customer who gave it one star and asked his local friends to do the same. The reason for this is completely unclear. As a result, the average rating has settled at very good 4.7 stars.