3 steps: (1) download app to iPhone, download app to Windows 10 or Mac; (2) pair your iPhone from PC app via Bluetooth; (3) login your PC via TouchID or FaceID. One iPhone is ready for multiple devices (Windows, Mac OSX). it's not just PC and Mac login, you can turn your iPhone as FIDO U2F (2nd factor) authenticator to login your web service securely. Contact us for volume license to your office, Corp or Organization.