http://www.iykpqm7jiradoeezzkhj7c4b33g4hbgfwelht2evxxeicbpjy44c7ead.onion/deeplinks/2017/09/guide-common-types-two-factor-authentication-web
Most sites that support U2F also support TOTP and backup codes. You can log in once on your mobile device using one of those options, while using your phishing-proof U2F device for logins on the desktop. This is particularly effective for mobile sites and apps that only require you to log in once, and keep you logged in.