The "Click&listen for spotify" extension searches for songs based on the text you select in your browser. You see the name of a song and wonder how it sounds? Or see a song you like? Simply select it, open the extension and play it in your browser. Subsequently you can add this song to one of your playlists or library by only using your browser! Spotify account is not needed, only to listen to the full song or to use the save to library/playlists function.
Please note that this is not an offical app from the developers of Spotify and is not associated with Spotify