GS Remote is not a Grooveshark product nor was it developed by us. This is a third party app that is used to control Grooveshark on your computer browser from your mobile device.
You will need their mobile app as well as the browser extension which is available on their site. Once the extension is enabled, refresh Grooveshark and you'll see "GS Remote" next to your display name, if you hover over "GS Remote" you will see "Pair with Device". This is where you enter your code. If you have further trouble please contact GS Remote directly (gsremote.com).