The most important thing you should do when you set up 2FA is to save the ten one-time recovery passcodes that are provided -- but do not rely on storing them on your mobile device. We recommend printing them out and keeping them in a secure location away from your computer.
Some authenticator mobile apps store account credentials on the mobile device itself (the Google Authenticator works this way). That means that if you lose or replace your mobile device, you will no longer be able to log into your Particle account unless you have one of the one-time recovery passcodes mentioned above. So if you know that you’re going to be replacing your mobile device, first disable 2FA on your Particle account, and then re-enable it using your new device.
Some other authenticator apps (e.g. Authy and 1Password) store credentials in their cloud, so they are not as problematic when a mobile device is replaced.