Study objective: Produce Girl Talk, a free smartphone application containing comprehensive sexual health information, and determine the application's desirability and appeal among teenage girls.

Design, setting, participants, and interventions: Thirty-nine girls ages 12 to 17 years from Rhode Island participated in a 2-phase prospective study. In phase I, 22 girls assessed a sexual health questionnaire in focus groups. In phase II, 17 girls with iPhones used Girl Talk for 2 weeks and answered the revised sexual health questionnaire and interview questions before and after use.

Main outcome measures: Participants' responses to the sexual health questionnaire, interviews, and time viewing the application were used to determine feasibility and desirability of Girl Talk.

Results: Girl Talk was used on average for 48 minutes during participants' free time on weekends for 10- to 15-minute intervals. Reported usefulness of Girl Talk as a sexual health application from baseline (6 participants) to follow-up (16 participants) increased significantly (35.3% vs 94.1%; P < .001). Knowledge improved most in topics related to anatomy and physiology (70.5% to 74.7% out of 7 questions), sexuality and relationships (76.5% to 80.0% out of 10 questions), and STI prevention (75.6% to 79.0% out of 7 questions). Most phase II participants (13 out of 17, or 76.5%) were exposed to sexual health education before using Girl Talk, but 16 out of 17 participants (94.1%) stated that the application provided new and/or more detailed information than health classes.

Conclusion: Girl Talk can potentially connect teenage girls to more information about sexual health vs traditional methods, and participants recommended the application as a valuable resource to learn about comprehensive sexual health.