Being often irregular in shape, accurate measurements of wounds are often challenging. Tracing or length measurement by the longest dimension are often inaccurate and time-consuming to carry out. Yet, proper wound area monitoring is essential for wound care. Instead of multiple clinical visits, which also increase the burden on health care systems and the associated expenses, patients can take the responsibility for their own wound progress. To allow for better decisions based on more quantitatively accurate data and address the problems mentioned, the “APD Skin Monitoring” app was created for patient self-monitoring of wounds through the automated area calculation, area graph plotting, and colourimetric analysis functions. With automated features, patients and even clinical staff can better utilize their smartphones for wound care. In this article, we describe the image processing optimization to improve the automated wound detection and demonstrated the use of the app using wound images from a patient volunteer.