Calm Harm is a free iPhone app developed by Stem4, a teenage mental health charity. It is designed to help individuals manage the urge to self-harm by providing immediate techniques and support. With over 2 million users, Calm Harm offers a variety of activities in categories such as Comfort, Distract, Express Yourself, Release, and Random. Additionally, the app includes a breathing technique to promote mindfulness and reduce tension.

Developed in collaboration with young people and Clinical Psychologist Dr. Nihara Krause, Calm Harm utilizes principles from the evidence-based Dialectical Behaviour Therapy (DBT). The app aims to break the cycle of self-harm behaviors, explore trigger factors, and build a 'safety net' of helpful thoughts, behaviors, and access to supportive individuals. Users can also journal and self-reflect within the app.

Calm Harm has received numerous accolades, including being named the 'Best Healthcare App of the Year' at the 2021 Health Tech Awards. It is a private, anonymous, and safe tool for those seeking support in managing self-harm urges. However, it is important to note that Calm Harm is not a substitute for professional assessment and individualized treatment.