Asthma affects nearly 1 in 10 teenagers in the United States and can seriously impact their health and daily life. Teens are expected to manage their asthma by taking medications correctly and paying attention to symptoms, but this can be hard. Adolescents are still developing the skills needed to manage their thoughts, feelings, and behaviors, and they often receive less help from parents during this time. Because each teen struggles in different ways and at different times, they need support that is personalized and responds to what is happening in the moment. Smartphones offer a promising way to help teens manage asthma well. However, most existing asthma apps do not use the full range of proven behavior-change strategies or adapt to what the teen is actually doing day to day. To address this gap, our team created Responsive Asthma Care for Teens (ReACT)-a system that collects data about each time an adolescent takes or misses a dose of medication and monitors symptoms. ReACT helps teens set goals, get feedback, notice barriers, and practice problem-solving skills. Early testing showed that teens liked ReACT and that it improved the skills needed for better asthma management. In this study, the investigators will pilot test ReACT in a study with 160 teens ages 13-17 who have poorly controlled asthma. Teens will be randomly assigned to use ReACT or a comparison intervention for six months. The comparison intervention provides basic asthma education and a place to log symptoms and medication use-similar to what they might normally receive in standard care. Investigators will look at how well the study procedures work across multiple sites and whether ReACT improves the skills that help teens manage their asthma. The investigators will also explore whether ReACT leads to better asthma control and quality of life. Teens will complete assessments at the start of the study, at three months, and at six months. The investigators will gather information through surveys and objective data such as medication use. By the end of this project, the investigators will know whether the ReACT system and study protocol are feasible and ready for a larger clinical trial, and will have early estimates of how much ReACT may improve asthma outcomes for teens.