Typically, when accessing a digital service or application, a user (“User”) is often asked to register, requiring that he fill out forms, enter a Captcha code and validate his membership by reply email. This process becomes a tedious and unwieldy task when the User must do so on a mobile device. The more logical choice is for the User to sign up or to register in real time, with the very mobile device he is already using via a process and user interface designed for the mobile experience. Simple Mobile Registration (“SMR”) is a one-step system for self-registration, authentication and account activation that provides simple and immediate access, via mobile device, to the features and functionality of third-party services or applications. Optionally, the User may, during the registration process, invite friends to also register in real time for the third-party services or applications.