Inclusion Criteria:  adult patients with hypertension (treated with three or less anti-hypertensive medications) and chronic kidney disease stage 3 or 4 managed in participating nephrology practices have a smartphone that they are willing to carry with them the majority of the time while enrolled in the study able to comprehend English, have ability to walk. mean blood pressure of <=180/100 mmHg from historical blood pressure readings in the electronic medical record able and willing to provide informed consent  Exclusion Criteria:  inability to provide consent or read or speak English had MI or stroke within the previous six months, diagnosis of dementia or cognitive impairment inability to walk already participating in another physical activity study belong to vulnerable population likely to receive a kidney transplant within 1 month of enrollment into the trial living in a long-term care or rehabilitation institution likely to have their care transferred to another facility outside participating clinic areas during the course of the study planning to travel or live consecutively out of the country for more than one month participating in another intervention trial, hypertension not managed by the nephrologist in the clinic prescribed more than three anti-hypertensive medications (i.e. resistant hypertension), any other reason they do not expect to be able to complete the study.