This study aims to develop and implement a preventive intervention through a mobile application to help pregnant women feel better emotionally and cope with the changes of pregnancy in a more positive way. The idea is to offer practical and accessible tools that allow them to better manage stress, emotions and preparation for motherhood. The intervention proposed in this study is based on psychological strategies that have proven to be effective, such as relaxation exercises, techniques to manage stress and strategies to improve mood, strengthen the relationship with the partner and foster the bond with the baby before its birth. The application is designed to accompany pregnant women from the beginning of pregnancy to the postpartum period. It has different programs that include weekly activities on various important topics, such as physical health care, emotional management, connection with the baby during pregnancy, preparation for childbirth and the first months of the newborn's life. To evaluate the effectiveness of this tool, a study will be carried out with pregnant women treated by the Catalan Health Service. Participants will be randomly assigned to one of two study groups: the experimental group (in which participants, in addition to the usual medical care offered during pregnancy, will have access to the programs and activities of the app organized in a weekly plan of 5 activities and will have to answer the study questionnaires at weeks 16 and 36 of pregnancy and postpartum) or the control group (in which participants will receive the usual medical care offered during pregnancy, but will not have access to the programs and activities of the app and will have to answer the study questionnaires at weeks 16 and 36 of pregnancy and postpartum). Women who use the app are expected to experience greater emotional well-being and a lower risk of developing mental health problems during pregnancy. In addition, they may feel more prepared for motherhood, take better care of their health, have a more positive birth experience and a lower risk of postpartum depression. These women are also expected to develop a stronger bond with their baby and adapt better to the new stage of motherhood.