 The use of digital health technology such as smartphones and wearable devices has the potential to revolutionize disease prevention, detection, and treatment. A recent surge in digital health studies has utilized to bring your own device, BYOD, approach, where participants voluntarily provide their digital health data using devices they already own. However, this study design may not support the collection of data from a representative random sample of the target population, resulting in biased study results and technology development. The paper proposes the Demographic Improvement Guideline to address demographic imbalances discovered in existing BYOD studies. This article was authored by Peter J. Ho-cho, Jayhen E., Ethan Ho, and others.