SpotSearch enables you to find the music you've heard on the radio or elsewhere but don't know the title to.
All you need to know is a part of the lyrics.
Enter the lyrics into the search box and press "Find the Song" and you'll instantly get links to either Spotify or on Youtube.
NOTE: There is a free version if you want to try it out first: "SpotSearch Free"
NOTE: You will need to have spotify installed on the phone to get the most out of this program. But without spotify you can still use the Youtube features.