I (finally) launched this side project to scratch my own itch of listening to lots of different mixes across different platforms (Soundcloud, YouTube, Mixcloud etc) but not having to have lots of different tabs open. Right now, it really is just a simple list of mixes you curate from different platforms to save you switching between different tabs / having to remember what you want to listen to, but it does remember your position on Soundcloud & YouTube mixes if you pause / exit and resume later in the same browser. Technically it also supports Apple Music and Spotify links, though Spotify embeds only gave me a preview of each track (even when logged in to a premium account) so that may not be practical other than adding a Spotify link as a reference for later. (Apple Music seems to be OK if you login, via the browser, after playback starts).

MixQueue

Listen to your favourite mixes from YouTube etc in one place

Listen to your favourite mixes from YouTube etc in one place