Inclusion Criteria:  Self-reported nonsmokers (for at least last year) Has own smartphone Systolic BP (SBP) at 120-145 mmHg Diastolic blood pressure (DBP) <95 mmHg Has history of hypertension with ≤ 3 medications and stable without change in past 3 months If medications are used, there should be no change in dosage during the 28-day study period.  Exclusion Criteria:  Living with an active smoker who smokes indoors Left upper arm circumference >17 inches (measured by tape measure upon recruitment as needed as it makes the home BP device inaccurate) Pregnant Unable/unwilling to consent Established cardiovascular disease (CVD) Stage IV clinical kidney disease (CKD) Clear barrier to technology use (e.g., visual or hearing impairment) Lung disease requiring oxygen Cancer receiving treatment Diabetes COVID-19 infections Any condition where the investigators believe the risk of a mildly high BP above 130/80 mmHg may pose risk to the patient during the 28-day period of the study including but not limited to aortic aneurysms