Spotify is, of course, a streaming music service, but on the desktop, the app will also catalogue and let you play the MP3s on your hard drive.

For music not in Spotify’s online library, the company does let you transfer music to your special Spotify library using sync from your desktop, which is a somewhat awkward process when many young people rarely use a PC.

Now it appears Spotify is working on detecting and playing music you have on your smartphone without having to sync if from the desktop.

This new feature was discovered by reverse engineer Jane Manchun Wong, who tweeted this:

This means for example if someone sends you an MP3 over WhatsApp you will now be able to play it alongside your regular Spotify tunes in the same app.

It appears the feature will be activated via a toggle in Settings.

It is unfortunately not clear if and when Spotify will roll this feature out.