Stress can have a negative effect on overall well-being, trigger physical disease, and contribute to mental health disorders. The 10-item Perceived Stress Scale (PSS-10) is frequently used in research. However, there are limited studies on the test-retest reliability of the PSS-10 with adults, and no studies could be identified that tested this issue with adolescents. Meditation apps are often recommended for stress reduction, but they have not been widely studied for use in high school. This study investigated the test-retest reliability of the PSS-10 and examined the feasibility of using a meditation app with high school students. First, a comprehensive review examined prior studies of PSS-10 test-retest reliability. Second, the test-retest reliability of the PSS-10 was investigated with a sample of high school students over 24-hour, 3-week, 6-week, and 9-week time intervals. Third, the test-retest reliability results from the high school study were compared to the results from comparable intervals in prior studies. Finally, the frequency of independent use of the meditation app was measured, and thematic analysis was used to explore the students' experience. Most significantly, this study appeared to be the first one to investigate the test-retest reliability of the PSS-10 exclusively with an adolescent population. Quantitative results showed that the PSS-10 demonstrated excellent 24-hour test-retest reliability but may not be stable for longer intervals. Frequency analysis confirmed that most students did not use the meditation app independently. However, evidence from qualitative findings indicated that the meditation app showed promise for use in a high school curriculum. This study provides several recommendations for the use, analysis, and interpretation of the PSS-10 with both adults and adolescents. It also outlines a plan for high school stakeholders who would like to advance the use of a meditation app. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]