Background: Telehealth improves access to health care and potentially leads to better clinical outcomes. However, digital competence could be an essential factor in ensuring its adoption, particularly among older adults. This study evaluated the acceptability and perception of a mobile application platform among Thai older patients with chronic diseases according to their demographics and digital skills. Methods: The demographic information and internet usage profiles of patients with nonmalignant chronic diseases, including chronic viral hepatitis, were collected. Participants were grouped based on their self-perceived digital familiarity. The chi-square test was used to evaluate the associations between the parameters. Results: Among 710 participants (61.7% women, mean age: 66.2 years), digital familiarity was significantly higher among individuals aged <70 years, men, those with a bachelor's degree or higher, those with higher incomes, and Bangkok residents (p < 0.001). In this study, regular use of smartphones and the internet, but not messaging applications, was associated with self-perceived digital familiarity. Of these, 100 participants completed a survey evaluating their satisfaction with and perceptions of telehealth. Participants with greater digital familiarity demonstrated significantly higher satisfaction with telemedicine compared with those with limited ability or relied on caretakers (χ2 = 70.145, p < 0.001). Conclusion: Our data indicated that a user-friendly mobile application is feasible and acceptable for the management of chronic diseases in older patients. Digital familiarity is an important factor associated with satisfaction with the platform, underscoring the need to bridge digital skill gaps and ensure equitable health care delivery.