In this talk I show the app that I've made in two months while learning the Flutter framework. It was built on open data and open source libraries. But what separates it from the rest is not code - but experience. Maps on mobile screens are hard to do properly, and there's always a temptation to add another screen, another button. Turns out you need a bit more than skills to make a perfect app: at least you need to use it daily. Last year I moved to Tallinn, Estonia, which is known also by it's public transport system - free for city residents. It is so good, reliable and optimized, that I sold my car and use buses and trams exclusively for all my city travels. While planning a transit route is pretty straightforward with an official website, usually I need some transit-related information on the go. On a phone. And that's where both the website and many big and small apps show their imperfections. Download sizes, ads, user interface. Instead of focusing on my problems, I have to learn and work around apps' issues. As an open source developer, that seemed not an issue - but a challenge. I've made interactive maps for the past ten years, and I know one should not use these libraries with default settings. Nor one should ever rely on zooming. Could I made a map with apps that doesn't require more than a couple of taps to get all the needed information? How hard would it be to keep number of buttons and other interactive elements to minimum, while not sacrificing functions I need every day?