As mentioned in the article, the litigations being levied against Grooveshark are part of the reason that their official app got yanked from the App Store.
While Grooveshark’s legality might be questionable, it was still the service that introduced me controllable streaming radio solutions later popularized by Rdio, Spotify, MOG, etc. And while I used it and paid for a pro membership for a short time years ago, I now choose to support services that I find to be at least a little more legitimate (I’m an Rdio fan myself). It was always an easy to use service, and I still think that Grooveshark’s playback and library management are both far superior to Rdio and Spotify. The kids that started the company are crazy talented too. It’ll be interesting to see where they go, because I honestly didn’t think they were gonna win this one.