You don't have to pay to listen online. The $2.99 is if you want to upgrade the stream to near CD quality sound (128K). I am a lifetime subscriber to Sirius, have been for 5 years and can listen online, in fact, I am listening online right now.
I don't pay for the option to listen online. Whenever I launch the player, I get an option to upgrade to Sirius Internet Radio for $2.99 per month.
I haven't tried the Sirius app on my Droid, but I imagine it would not work since I have not upgraded the Sirius Internet. You can still listen on a computer to a less than 128K stream.
Edit: forgot to mention that the $2.99 would also allow you to listen on your Droid. As long as you are already a subscriber you can stream the less than 128K stream for free on a computer.
You might be a lifetime subscriber and maybe you are getting Sirius for free on the internet, but nobody else can. I've been subscribing for 5 years also and I can't get it on line anymore because I turned down the 2.99 per month payment for the on line service. I am not a lifetime subscriber. That may be why you get it for free.