Updated, 8:15 p.m.: I heard back from Kluivers, and without going into details, he was concerned that Apple was taking a long time to approve Lyrics--he submitted it in January, but didn't get it approved until earlier this month. Consequently, the explicit filter was made very protective, to avoid any chance of offending the App Store gatekeepers. Jelle Krins, who co-developed the app, told me of an Easter Egg that lets you turn off the filter: just scroll all the way to the bottom of the "About" screen three times, and a filter on/off button appears. Turn it off, and the app works flawlessly.
When I looked at iPhone song lyrics application LyricsFind last month, I found too many gaps to make it worth paying for. Earlier today, programmer Joris Kluivers pointed me to a much better alternative that he created called Lyrics, which costs $1.99 in the U.S. and has became available in the iPhone App Store last week.
The Lyrics app draws on the excellent LyricWiki.org site, which contains crowd-sourced lyrics for more than 700,000 songs. I love the site: it uses an embedded domain-specific Google search bar, which delivers great results. And if you're pedantic about your favorite bands' lyrics like I am, you can easily change lyrics that you just know are wrong--for example, in "Chip Away," Perry Farrell is obviously saying that he and the angel "both wore dirty faces," not that they "both were dirty faces," so I changed it accordingly. (Some songs, like REM's "It's The End of the World As We Know It," have been locked because so many people have different interpretations. The version up there now checked out perfectly against the audio track in iTunes, so I can't quibble.)
Unfortunately, while the Lyrics iPhone app draws on a great source, it's ruined by a persistent bug: it thinks perfectly innocuous songs like Led Zeppelin's "The Immigrant Song" and Pink Floyd's "Echoes" contain explicit lyrics. Maybe they're erring on the side of caution to avoid getting blacklisted like Trent Reznor recently did, but using it felt like listening to a crazy person muttering about how all the songs on the radio today are filth.
Follow Matt on Twitter.