No, if you do not want to download and install the Authy app, you can always use a YubiKey as your preferred method of two-factor authentication.
Authy 2FA gives you multiple options for obtaining codes. You can use the mobile app for Android or iPhone or a desktop app which runs as a Chrome extension. Authy apps are instant, do not require continuous internet connection and the desktop app makes two-factor authentication a seamless experience.
You can find out more about these options on the Authy blog: http://blog.authy.com/multi-device
Read more here: https://authy.com/features/#better
A YubiKey is a small device that you register with your Coinfloor account and use every time you sign in. Phishing, malware, and other attack methods don’t work because they would need both your physical key and your passwords to breach your account.
You can find out more about YubiKeys here: https://www.yubico.com/why-yubico/for-individuals/and here: https://www.yubico.com/2015/11/why-yubikey-wins/
You can purchase a compatible YubiKey on Amazon. Coinfloor supports 44-character YubiKey tokens. If you are a YubiKey VIP user, please use slot 2 to generate a valid token. FIDO U2F Security Key is not a compatible key.
If you've changed your phone number or wish to switch your 2FA method from Authy to YubiKey, please follow the instructions for 2FA reset.