The project will develop and test an innovative, low-cost and effective solution to maternal mental health problems in the context of pregnant youth (aged 14-22) living in adverse conditions in urban areas of a megacity. Motherly, a smartphone app, will promote maternal mental health and child development. The app will be visually appealing and provide an engaging user experience, enhancing participant engagement. The app will offer a gamified experience, ideal for engaging youth in behaviours that can promote mental health. Participants will be awarded with points and badges, based on behaviours and interactions with other participants.