Multiple sclerosis (MS) is a lifelong neurological condition affecting around 2.2 million people worldwide. There are a wide range of symptoms, with fatigue reported as one of the most troublesome. MS Energize—or MS Energise in UK English regions—is an iPhone app focused on self-management of fatigue for people with MS. Based on cognitive-behavioral therapy principles, the app covers MS fatigue, how to use energy effectively, how behavior, thoughts and emotions interact and impact on MS fatigue, as well as the potential effects of bodily and environmental factors. MS Energize provides education, interactive tasks, and supports application of the principles into a user's day-to-day life.

We field tested the usability and perceived usefulness of MS Energize with 11 people with longstanding multiple sclerosis in New Zealand and the United Kingdom. Participants used the app over a period of five to six weeks after which they rated the usability of the app and participated in an in-depth qualitative interview.

We developed four main themes through our thematic analysis. 1. Validation of participants' own experiences of living with MS fatigue. 2. The personal cost in engaging with such an intervention. 3. Reframing experiences and adding to knowledge. 4. That the app was generally a good idea. Field testers' feedback also identified usability issues that could be addressed. In particular, the amount of text-based content in the app contributed to the app itself being fatiguing. This field-testing process has highlighted the value of the app while also guiding our roadmap for further developments to enhance usability and usefulness. The next step is further refinement of components of MS Energize in preparation for a trial of its clinical and cost effectiveness.