title: Reference guides.
abstract: iPhone users can add a new free app to their collection courtesy of the Scottish Intercollegiate Guidelines Network (SIGN). The app launches with quick reference guides to its most recently published guidelines, which include help in areas such as rheumatoid arthritis, venous thromboembolism, psoriasis and psoriatic arthritis in adults, and chronic venous leg ulcers. There are also guidelines on the management of sore throat and indications for tonsillectomy, diabetes, obesity and pharmacological management of Parkinson's disease.