I've been a big fan and a user of the original Transparent Speaker released in 2013, where I was able to connect Airport Express for Airplay or any other dongle (Google Cast or other USB Bluetooth) and embed it into the speaker with super clean design and tight sound. A novel idea at the time has now turned into a new smaller version promising even better integration with built-in AirPlay, Cast, Bluetooth, Spotify.
More importantly, I like the concept of up-cycling, i.e. thinking about what happens with the product once it's outdated or breaks. You can easily send it back for full recycling/replacement and get a discount when buying a new one.
Light Speaker