KaiOS is the biggest growing mobile OS on the market at the moment with over 80 million devices already running it. It is currently the second biggest OS in India already. The OS is andriod-based (forked from Firefox OS) and most app compatibility comes from web versions, for example Telegrams web.telegram.org. Most websites already work out of the box, however the Spotify Web player demands you to install their app, which is yet non existent.
While we wait for an official Spotify App (which could take a while), we ask Spotify to open the Spotify Web player to KaiOS systems, so we can continue to enjoy Spotify.