Sync lyrics from FloatingLyrics
In order to sync the lyrics with the music, you'll need to be able to play the song and control it from the Musixmatch app.
You can either connect to a Spotify Premium account or have the song downloaded to your device's library.
Once you have the possibility to play a song from the Musixmatch app, you can directly sync the song you're listening to from another music app. Otheriwse, you can look up the song you'd like to sync on, and tap on the colored dots icon to start syncing the song.