Feasibility, Engagement, and Usability of a Remote, Smartphone-Based Contingency Management Program as a Treatment Add-On for Patients Who Use Methamphetamine: Single-Arm Pilot Study. - Hallgren KA; Duncan MH; Iles-Shih MD; Cohn EB; McCabe CJ; Chang YM; Saxon AJ (JMIR formative research, 2023)