The L-TRiP(cast) score was developed in the Netherlands, using data from a large population-based case-control study in patients with lower limb trauma requiring orthopaedic immobilisation. Such patients are at higher risk of thrombosis but also experience risk from anticoagulation. This study and this App aid with decision-making in this regard to allow the clinician to have a meaningful discussion with such patients regarding the need for prophylactic anticoagulation