This work is part of a planned larger project to develop an intelligent mobile personalised guidance service for the management of diabetes by harnessing the power of the new generation of smart phones. Existing mobile applications enable diabetic patients to record blood glucose readings, carbohydrates consumed, insulin dosage, physical activity undertaken, and other activities and observations. Our aim is to develop a lightweight ontology that captures the kinds of information recorded by such applications, and which would facilitate interoperation. In order to establish a list of terms that must be captured by the ontology, we have undertaken a systematic review of applications (limited, for the moment to the iOS platform). We use this list to establish suitable classes and properties for the ontology, and then investigate how it can be mapped on to existing standards such as HL7 RIM and OpenEHR.