The company's use of the "Authy" app for two-factor verification renders the site useless if there is an error. If you have an issue with the app, change your phone number or lose your password, you will NOT be able to get back into your account. Gemini will NOT help you, and Authy is a terrible company with a buggy app. Buyer beware! It's a shame because the rest of the exchange is decent, they're just too stupid to fix this issue.