[infinity85]

Is a real spotify connect function going to be included?

There already is, including discovery support. Maybe you need to enable avahi support in Kodi settings --> services.

Thanks for your fast reply

So you mean the "zeroconf" setting? I cannot find a "avahi" one, but zeroconf should be it, right?
Still no Spotify Connect (kodi)device showing up in my Android Smartphone app.

My steps:
1. Installing your addon on LibreELEC 8
2. Rebooting my Device
3. Opening the Spotify app on my Smartphone to see kodi as a spotify connect device (my AVR shows up, Kodi does not)
--> discovery doesn't work here or I misunderstand the mentioned "discovery" feature. However, with the LibreSpot addon made by @awiouy from LibreELEC forums it works right out of the box. My Smartphone app shows LibreSpot@LibreELEC as a device directly after boot.

(I did not input any credentials in your addon)
Here's the kodi.log (don't wonder about Amlogic stuff... it is an Odroid with 32Bit libs, thus fully compatible with Raspberry pi2/3 addons)