Grooveshark has decided to try and circumvent the issue of not being on web stores by unleashing a gambit Apple and Google can't shut down: a mobile HTML5-based client. Grooveshark has had a contentious relationship with the App Store and Android Market, having pulled off the rare double whammy of being removed from both the App Store and Android Market! Some of the major music labels, like Universal, dispute the legality of the service in part because they believe that Grooveshark is willingly permitting copyright infringement, although they do have deals with some labels.
As such, the idea of an HTML5 player is to be something that will work on mobile devices without approval from companies who also have financial agreements with the record labels who oppose their service. The HTML5 player works in Safari on iOS, on browsers for Android 2.3 and later, including third-party browsers. While this HTML5 solution doesn't allow for offline listening or continuous track playing, it allows for the easy streaming of music on mobile, all without needing an app. The HTML5 player, which is still in a beta form, is available from http://html5.grooveshark.com and is currently free to access.