Inclusion criteria:  >18 years old; owns a smart phone; has access to WiFi or willing to use mobile data; has an email address or willing to create an email address; able to read and understand English; able to give informed consent; willing to receive text messages and complete brief questionnaires on their smart phone.  Exclusion criteria:  unwilling to have sedentary behavior and activity tracked unable to walk without ambulatory assistance device (i.e. cane or walker) or due to underlying medical condition.