Navic is completely free and open source.

Navic is not yet stable and is in a pre-release alpha state. However, most things should work just fine!

Most Subsonic clients are closed source. This project was started in hopes of making an open and free alternative. Additionally, most clients just simply don't look very pretty, and we wanted to fix all of this. Navic is also native, making it one of the faster and efficient clients. It uses Compose and Kotlin.

For now, no. However, some plugins for other services have been made to add compatibility with Subsonic clients.