This study investigated the effect of digital therapeutics on ROM, flexibility, dynamic balance, satisfaction, and adherence. A sample of 34 volunteers was randomly assigned into a Digital Therapeutic Group (DTG) (n = 17) and a Non-Digital Therapeutic Group (NDG) (n = 17). The groups performed four calf muscle stretches and two hamstring stretches for 4 weeks. Flexibility and balance were evaluated to assess the effectiveness of the exercise program. A survey was conducted to assess subjects’ satisfaction, and exercise performance record papers and video records were assessed for exercise adherence. The paired t-test was used to compare the two populations before and after the program. The independent t-test was used to compare the change scores between groups. In the pre- and post-comparison within each group, the DTG group showed significant differences in all items except the dorsiflexion range of motion (ROM) (p < 0.05). The left straight leg raise (SLR) was significantly different (p < 0.05), and there was a significant difference in exercise satisfaction and participation between the two groups (p < 0.05). DTG showed improved flexibility, dynamic balance, and higher exercise satisfaction and adherence than NDG. The application, providing lower extremity stretching, can improve dorsiflexion ROM, flexibility of the lower extremity, dynamic balance, exercise satisfaction, and exercise adherence.