Digital behaviour change interventions can provide effective and cost- effective treatments for a range of health conditions. However, after rigorous evaluation, there still remain challenges to disseminating and implementing evidence-based interventions that can hinder their effectiveness ‘in the real world’. We conducted a large-scale randomised controlled trial of self-guided Breathing Retraining, which we then disseminated freely as a digital intervention. Here we share our experience of this process after one year, highlighting the opportunities that digital health interventions can offer alongside the challenges that must be addressed in order to harness their effectiveness. Whilst such treatments can support many individuals at extremely low cost, careful dissemination strategies should be proactively planned in order to ensure such opportunities are maximised and interventions remain up-to-date in a fast-moving digital landscape.