Phase 2 will focus on an evaluation of whether an adaptive app offering tailored content addressing eating related cognitive distortions in a stepped way can outperform the current standard app. The adaptive content will be integrated into a new, dynamic version of the app (RR-A) that will then be evaluated against the current app (RR-S). Approximately 5,000 registered users of RR will be randomized to receive either RR augmented with targeted content (RR-A), or RR in its current standard format (RR-S) over a two-month period. Outcome data will be measured at baseline, one month, end of treatment, and at six-month follow-up. At the end of the study period it is predicted that the resultant evidence-based product will have demonstrated ability to bring about clinically significant reduction in symptoms in more users than the current app, and thus will have potential to make a substantial public health impact.