I run https://mapchart.net which is a map chart creation tool. You can quickly create a map chart of World, USA, UK, Europe and more with custom colors and descriptions.
It is completely free to use and my only source of income are Adsense ads on the homepage and some sparse donations. Since May, when the site was featured on the front page of Reddit, my audience has increased with a steady rate, along with my ad revenue (almost $500 last month).
I don't really do anything maintenance-wise, except for answering questions from my users. I work on it from time to time, mainly adding new features or new country/regions maps, and I still enjoy it, as it was my first real programming project (I actually submitted it as a final project for EdX's CS50x course!).
It is completely free to use and my only source of income are Adsense ads on the homepage and some sparse donations. Since May, when the site was featured on the front page of Reddit, my audience has increased with a steady rate, along with my ad revenue (almost $500 last month).
I don't really do anything maintenance-wise, except for answering questions from my users. I work on it from time to time, mainly adding new features or new country/regions maps, and I still enjoy it, as it was my first real programming project (I actually submitted it as a final project for EdX's CS50x course!).