Compatible with iOS 9 and 10
Déjà vu is a tweak which improves the creation of playlists in the Music app. No longer will you have to guess if a song is already on a playlist, and end up with multiple duplicates.
When adding songs to a playlist Déjà vu will grey out songs that have already been added. It will also display a warning if you try to add one of those songs. These can both be toggled in settings.
It also applies to the 'Now Playing' and 'All Songs' views where pressing the 3 dots next to a song lets you add it to a playlist. Any playlists that already have that song will be greyed out.
Configure options from Settings.