The 21Things4Teacher site's goal is to provide a single site of free resources and tutorials which meet the international educational technology standards, and offer any-time training to be used for professional development. Its resources are designed to serve a variety of models for professional development.
Teachers can pick and choose the elements they want to know more about. Teachers are able to access both the linked tutorials and the more in-depth recorded training sessions whenever they want them (anytime-anywhere). Any educator is welcome to use the site for training on an as needed basis, and all are free to do so. However, those wishing to obtain credits or certifications must enroll in the course taught by a certified trainer (Agency Coordinator).