I really enjoy searching the lyrics for the song I'm listening to on Spotify at the moment.
I especially like searching for lyrics on Genius, which provides me with context that I would otherwise miss.
After noticing that I had been doing this over and over again, I decided to build a very small application in a couple hours after dinner: nowplayinglyrics.com.
Now Playing Lyrics is a Laravel app that uses the Spotify API to fetch your currently playing song, then searches that song on Genius using their API, and redirects you automatically to the first search result.
During the development of the app I've found that Spotify's API was not updating properly at times. I've filled an issue in their GitHub repository and their team was very quick to get back to me with a fix.
The code for Now Playing Lyrics is available on GitHub under the MIT license.