OBJECTIVES: The COPD Assessment Test (CAT) is a short, validated questionnaire designed to measure the impact that Chronic Obstructive Pulmonary Disease (COPD) has on the wellbeing and daily life of people living with COPD. The eight items pertain to COPD symptoms and impact on life, and are rated using a six-point scale, ranging from zero to five. From its original paper validation, the CAT has migrated through to many electronic platforms such as the web, tablet devices, and hand-held devices. Usability testing studies have been conducted to test the migration of the CAT to these platforms. The results have proved that the migration does not alter the way in which the items are interpreted and how the questions are completed by people with COPD. More recently, the CAT has been developed for use as a smart phone app to increase accessibility for people with COPD. METHODS: A qualitative study was conducted to test the usability of the app with ten people diagnosed with COPD. Participants completed the CAT using a smart phone, and were then asked questions that probed on the usability of the questionnaire as a smart phone app. RESULTS: Due to the CAT being short and concise, the smart phone app works very well for hosting such a questionnaire. Navigating around the screen and selecting responses to the questions were completed with no major concerns for half of the patients. Others commented that the app version could benefit from the functionality of manually increasing the screen size, as this was not implemented before the usability testing was conducted, and is a common feature of smart phones. CONCLUSIONS: Although some further work is still required before the app is finalised, this study showed that the CAT has great potential for becoming accessible in many different electronic platforms.