iPhone: Shuffling your music is usually a no-fuss affair. If you're looking for more features, however, Stringer is an app that gives you a lot of control over how shuffle works.
Stringer uses "strings" to shuffle music. You start a string with a song then Stringer builds out a shuffled set of songs. Then you can add, move and delete songs as you go. This way, you can easily listen to a few more songs on an album, add similar songs and whatever else without messing up the flow of the shuffle. If you're willing to pay the $6.49 in-app upgrade fee, you can also tag songs as favourites, hide songs, save strings and access a related artists feed. It's a nice way to curate your shuffled music feed while still keeping the fun of listening to music on shuffle.