MetaMood is a gamified Android application, developed from an existing paper-based health intervention program, designed to increase the motivation and engagement of participants. The development process followed a clinician-based design which was necessary to avoid exposing participants to an untested and unverified clinical tool. This paper describes design considerations and outcomes which could be useful for similar gamification attempts. It also presents the implementation and evaluation of a clinician review process, a vital step required before a full clinical trial. The success of MetaMood, evaluated through the results of the clinician review, suggests that a similar design, development, and evaluation process should be followed by future mobile e-health interventions before they are released through a public App Store.