Update airsonic.md

wiki/airsonic.md

@@ -14,4 +14,7 @@ As already mentioned it is possible to use a bunch of different clients because
 the server is compatible with most of the Subsonic clients.
 
 - [Ultrasonic](https://www.f-droid.org/en/packages/org.moire.ultrasonic) is a
-  free and open-source android subsonic/airsonic client.
+  free and open-source android subsonic-compatible client.
+- [Sonixd](https://github.com/jeffvli/sonixd) is a
+  free and open-source cross-plattform subsonic- and jellyfin-compatible client.
+  It uses a look and feel similar to the spotify client.