RecruitingPhase 2Behavioural interventionUsing Mobile Stress Management to Reduce Hypertension in African American MenThe goal of this clinical trial is to learn whether a smartphone-based stress management program can reduce blood pressure and perceived stress in Black men with hypertension. The main questions it aims to answer are: Does a mobile cognitive-behavioral stress management intervention (m-CBSMi) reduce systolic and diastolic blood pressure more than a standard online stress management course over 6 months? Does the m-CBSMi reduce perceived stress more than a standard online stress management course over 6 months? Researchers will compare participants assigned to the m-CBSMi - a culturally tailored program delivered via text message and video - to participants assigned to the "Diploma in Stress Management" course on Alison.com, to see if the m-CBSMi produces greater improvements in blood pressure and stress outcomes. Participants will: Complete a phone-based survey at baseline and again at 6 months Attend two in-person blood pressure measurement visits at the partnering clinic, one at baseline and one at 6 months Complete their assigned stress management program (m-CBSMi or the Alison.com course) over 3 months, delivered via smartphone