Adapting a Mobile Health App for Smoking Cessation in Black Adults With Anxiety Through an Analysis of the Mobile Anxiety Sensitivity Program Proof-of-Concept Trial: Qualitative Study - Marshall K Cheney; Adam C Alexander; Lorra Garey; Matthew W Gallagher; Emily T Hébert; Anka A Vujanovic; Krista M Kezbers; Cameron T Matoska; Michael J Zvolensky; Michael S Businelle (JMIR Formative Research, 2025)