With Napster, you can add or remove devices from your account any time. One note, if you're going to de-authorize a device, the songs you've downloaded on to that device will not play once you've de-authorized it.
For more information on compatible devices, see this page. At this time, Napster is not compatible with iPod Nano, iPod Shuffle, iPod Classic, Sony Walkman, or Philips MP3 players.
ADD A DEVICE
Add or re-authorize a mobile phone or tablet:
1. Get the app.
2. Sign in to your account.
3. Start playing!
REMOVE A DEVICE
Remove a phone, tablet or MP3 player:
1. Login to My Account.
2. Click "Authorizations."
3. Scroll to "My Authorized Phones and MP3 Players."
4. Click "Deauthorize" next to a device to remove it.
5. You can now add another device.
Remove a computer:
1. Login to My Account.
2. Click "Authorizations."
3. Scroll to "My Authorized Computers."
4. Click "Deauthorize" next to a computer to remove it.
5. You can now add another computer.