Together with Thomas Konrad we wanted to build a new interface to openstreetmap-data. We were both quite frustrated at the state of the current openstreetmap.org so we set out to create our own little application.
Besides, we were looking for an excuse to get our hands dirty with AngularJS, which at the time we started the project was at v1 😯. (We later migrated it to Angular 2)
Since this was a side project for both of us, it never really took off. Nevertheless it was a great learning experience both in terms of using Angular and TypeScript as well as combining different mapping APIs (Overpass API, komoot photon, Mapbox SDK, ...).