Slacker is stepping up their game with the announcement that they will offer on-demand services for Android, iPhone, and Blackberry apps. The service will cost you $9.99/monthly and will offer the ability to play specific songs straight from their database of millions of songs over Wi-Fi or 3G. With this service you will also get all the features that come with their Radio Plus service. Now the Radio Plus service alone is $3.99/monthly and it offers the ability of unlimited skips, offline caching, and no ads. So if Slacker is your cup of tea you may want to check out their new premium service.