Worries about harm from others (also known as paranoia) are common. Thinking fast or going on gut feelings is natural but can fuel these worries. For some, fast thinking and worries start to get in the way of life. Cognitive behaviour therapy for psychosis (CBTp) is the recommended talking therapy. However, only a minority of people can access CBTp due to limited resources, and even when available, therapy can be difficult to do and use in daily life. SloMo is a digitally supported therapy that aims to overcome these barriers, and was developed by people with psychosis, designers, and psychologists. It supports people to notice worries and fast thinking habits. During therapy sessions, people learn to slow down and feel safer. Personalised spinning thought bubbles are slowed down using SloMo tips. An app provides access to helpful messages. SloMo was previously tested in a randomised trial of 361 people attending mental health services. SloMo was found to be safe to use, with no adverse events linked to the software. People in the SloMo group had lower paranoia, and better confidence and wellbeing, over 6 months compared to people who just received their usual care. People found SloMo enjoyable and easy to use. The next step is to evaluate if SloMo can be safely and effectively delivered by therapists working in NHS services. If SloMo works in routine care, the therapy will be made more widely available in the NHS. An improved version of SloMo has been co-produced based on feedback. Sixty therapists will be trained and supervised in 3 trusts to deliver SloMo to 150 people who fear harm from others. Safety, technical performance, uptake, engagement and acceptability data, alongside interviews with patients, therapists, and managers, will investigate how SloMo is used. Paranoia severity and wellbeing will be measured pre and post therapy to find out if SloMo helps. Service use data will evaluate costs and savings.