This paper presents the HealthMon framework towards accessible mobile health. Following the emergence of wearables with rich sensing capabilities in the market, HealthMon repurposes an affordable, retail wristband to clinical monitoring scenarios for conditions that impair independence e.g. dementia, Parkinson's or ageing. Multiple sensor modalities, such as physical activity levels, posture and heart rate, are unanimously stored and interpreted to produce real-time alerts, using Semantic Web technologies. HealthMon's constant monitoring capabilities are available to end-users and informal carers e.g. family and medical doctors alike, through mobile and web applications. The framework focuses on adoptability and deployability, receiving positive user feedback.