Flashcards are with us from our very earliest learning experiences. As infants, we learn to speak words from flashcard pictures. As toddlers, we are introduced to vocabulary concepts and thinking skills with flashcards. In early learning experiences we learn facts, languages, associations, and even social skills. Flashcards remain highly prevalent in higher education, especially medical education, vocabulary, language learning, as well as mathematics and psychology. Learners at the highest levels augment their knowledge with flashcards. What actually makes these learning tools so ubiquitous and, ultimately, effective? Two major components of how flashcards work are the "testing effect" and "spaced repetition." The purpose of this quasi-experimental study was to understand the relationship between these elements and flashcard use, particularly in an athletic setting. Athletic coaches spend a considerable amount of time teaching basic factual information (lower level) to their athletes. As a result, less time is spent on higher-level learning such as applying and analyzing. A secondary purpose of this study was to determine if flashcards can effectively be used to help athletes demonstrate higher-level application principles. To accomplish this, this study introduced an asynchronous, digital flashcard app as an intervention tool for high school American football coaching. The results showed that students who used the intervention tool outperformed those in the control group. The study also found that students who used the tool at the prescribed amount (three times per week for 15 minutes) realized a 29% increase in their post-test exam scores. Lastly, results showed evidence of students demonstrating application principles during in-person practice sessions. [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.]