Sign in to SMS Mobile App

SMS Mobile App uses Google OAuth as its only sign-in path — no email/password to manage, no third-party identity providers, no SMS-OTP loop. Sign-in unlocks unlimited personal sends (subject to your carrier rate) and the option to turn on batch sending across your own registered devices (opt-in per device, off by default; controllable in Settings). The 10 guest test sends do not require sign-in.