Koel Player is a music player for Koel, an open-source music streaming server. In a nutshell, Koel allows you to host and play your own music (imagine Spotify, but with your own mp3 collection). There's always been a responsive layout for mobile devices, but the user experience is sub-par due to the limitations of mobile web technologies. Koel Player is built as a native mobile app to solve this problem and provide a better UX.

The app itself is 100% open-source, but one can purchase and download it from AppStore (Google Play counterpart coming soon) to support the project.