Inclusion Criteria:  Able to understand and willing to sign a written informed consent document  HIV positive. Documentation of HIV-1 infection by means of any one of the following:  Documentation of HIV diagnosis in the medical record by a licensed health care provider; Documentation of receipt of antiretroviral therapy (ART) (at least two different medications that do not constitute a prescription for pre-exposure prophylaxis [PrEP] or post-exposure prophylaxis [PEP]) by a licensed health care provider. Documentation may be a record of an ART prescription in the participant's medical record, a written prescription in the name of the participant for ART, or pill bottles for ART with a label showing the participant's name; HIV-1 ribonucleic acid (RNA) detection by a licensed HIV-1 RNA assay demonstrating > 1000 RNA copies/mL; Any licensed HIV screening antibody and/or HIV antibody/antigen combination assay confirmed by a second licensed HIV assay such as a HIV-1 Western blot confirmation or HIV rapid multispot antibody differentiation assay.  Note: The term "licensed" refers to a kit that has been certified or licensed by an oversight body within the participating country and validated internally (e.g., U.S. Food and Drug Administration [FDA]).  WHO (World Health Organization) and CDC (Centers for Disease Control and Prevention) guidelines mandate that confirmation of the initial test result must use a test that is different from the one used for the initial assessment. A reactive initial rapid test should be confirmed by either another type of rapid assay or an E/CIA that is based on a different antigen preparation and/or different test principle (e.g., indirect versus competitive), or a Western blot or a plasma HIV-1 RNA viral load  Receiving antiretroviral therapy and CD4 count at least 200 cells/uL within 6 months of registration (due to increased risk of LDCT false positivity with CD4 count < 200cells/uL) Age 45-80 years. This age restriction reflects lung cancer risk and appropriateness for lung cancer screening; in epidemiologic studies lung cancer emerges 5-10 years earlier in PLWH, and therefore this is an appropriate risk group for screening. Although younger persons are likely to benefit more from smoking cessation as a lung cancer prevention measure, the risk/benefit ratio associated with lung cancer screening is unlikely to be optimal at ages < 45 years for PLWH Biochemically confirmed current smoker (exhaled carbon monoxide [CO] >= 7 parts per million) Meets United States Preventive Services Task Force (USPSTF) criteria for LDCT (age 50-80 and >= 20 pack-years smoking) or high-risk but not meeting USPSTF (age 45-49 and >= 20 pack-years smoking) Possession of a smartphone that can support Positively Smoke Free Mobile (PSF-M) (> 95% of subjects had eligible phones in prior trials although researchers will include specific study screening questions assessing for adequate smartphone for the intervention) Sufficient literacy; >= 4 on the Rapid Estimate of Adult Literacy in Medicine-Short Form (REALM-R) literacy scale  Exclusion Criteria:  Receiving any other smoking cessation interventions currently or within the prior 30 days Contraindication to nicotine replacement therapy Pneumonia or serious lung infection in prior 12 weeks Uncontrolled intercurrent illness including, but not limited to, ongoing or active major infection, malignant tumors (unless these tumors were: (a) completely resected basal cell or squamous cell skin carcinomas or (b) in-situ squamous cell carcinoma of the cervix or anus), or any other major uncontrolled comorbid condition that would limit life expectancy or psychiatric illness/social situations that would limit compliance with study requirements History of lung cancer Pregnant women are excluded from this study because computed tomography introduces radiation exposure and may have teratogenic effects Women who are breastfeeding (the safety of nicotine replacement therapy has not been established with breastfeeding) Received a chest computed tomography scan in the previous twelve months