Self-directed Mobile Mindfulness to Address ICU Survivors' Psychological Distress

Inclusion Criteria: Inclusion criteria present during hospitalization 1. Adult (age ≥18) 2. Managed in an ICU for ≥24 hours during the time inclusion criterion #3 is met 3. Serious acute cardiorespiratory condition, defined as ≥1 of the following: * mechanical ventilation via endotracheal tube for ≥4 hours * non-invasive ventilation (CPAP, BiPAP) for ≥4 hours in a 24-hour period provided for acute respiratory failure * new use of supplemental oxygen ≥6 liters per minute (or increase in baseline continuous oxygen) * use of vasopressors for shock of any etiology * use of inotropes for shock of any etiology * use of pulmonary vasodilators * use of aortic balloon pump or cardiac assist device for cardiogenic shock * use of diuretic intravenous drip * evidence of acute coronary ischemia (i.e., elevated troponin level, supporting EKG changes, unstable angina symptoms documented) * urgent cardiac catheterization 4. Cognitive status intact o No history of pre-existing significant cognitive impairment (e.g., dementia) as per medical chart 5. Absence of severe and/or persistent mental illness o Treatment for severe and/or persistent mental illness (e.g., psychosis, bipolar affective disorder, schizoaffective disorder, schizoid personality disorder, schizophrenia \[as per medical record\], hospitalization for any psychiatric disorder) within the 6 months preceding the current hospital admission 6. Functional fluency in English or Spanish (i.e., sufficient knowledge of English or Spanish to complete study tasks like watch videos, complete surveys) Inclusion criteria present after hospital discharge (i.e., at the time of arrival home after discharge from the hospital): 1\. Elevated baseline psychological distress symptoms, defined as a PHQ-9 score ≥5 Exclusion Criteria: Exclusion criteria present in the hospital: 1\. Discharged to a location other than a home setting (e.g., nursing home, long-term acute care facility, inpatient rehabilitation facility) Exclusion criteria present after hospital discharge (i.e., at T1 Data Collection conducted at the time of arrival home from the hospital): 1. Severe psychological distress as assessed by endorsement of active suicidality (see Protection of Human Subjects document for study team management of this finding) 2. Failure to randomize within 1 month after discharge from the hospital to home 3. Failure to login to study app and access content within 2 weeks after randomization