Since the Covid-19 crisis began, I spent a tremendous amount of time at home, so I needed to find an indoor activity. I chose mobile app programming, which I had long wanted to learn but had not time to do. After nine months of struggle, I could release my first app on Google Playstore (for Android smartphones only). The app name is 'Japan Culture Quiz.' It consists of four-choice questions about Japanese culture and miscellaneous things. I made it for those who plan to visit Japan and like to know about it before they come. If you are interested in it, please check out THIS LINK.
The questions in this app are all in letters, but the next app I am now preparing has a quiz with imaging.