Can i use two-factor authentication? CircleBack Support Updated October 26, 2016 01:18 Follow Yes, if you use two-factor authentication (which we highly encourage!) you'll be able to use our app. Related articles Are you reading my e-mail? Can I have multiple ContactSaver accounts? Why does ContactSaver manage my email? What does it mean? Why do I need a Gmail account? Why does a contact say "No Title or Company"? Comments 0 comments Article is closed for comments.