‘I gotta Feeling’: Exploring the effects of a smartphone app (Feelee) to enhance adolescents’ emotion regulation in forensic outpatient settings: A multiple single-case experimental design - Merel M. L. Leijse; Levi van Dam; Samantha Bouwmeester; Thimo M. van der Pol; René Breuk; Arne Popma (PLoS ONE, 2026)