Hah! Could de-track Riot.im by switching to miniVector :)
@vanitasvitae It's not quite the same but you can save Wikipedia articles for offline browsing with Wallabag. And you might be able to use Mopidy to access Spotify and stream from there to your phone with MALP. I haven't used Mopidy with Spotify, so no idea how well it works.
Fosstodon is a Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.