Can I generate codes for two-step authentication from more than one device?

Yes, you can. When you set up two-step authentication:

1.  Scan the QR code with an authenticator app on every device you want to use (e.g. your mobile and tablet).
2. Check all your devices generate the same 6-digit code.
3. Use the 6-digit code to complete the set up of two-step authentication and you're good to go.