Master's Thesis from the year 2021 in the subject Communications - Technical Communication, grade: 1,2, Technical University of Ilmenau, language: English, abstract: Introduction - Obesity is a contributing factor to many diseases and is becoming a growing problem worldwide. Many apps have been developed to assist users in improving their weight management. However, given the speed at which apps are created, it is crucial to assess their quality regularly. Objectives - This study aimed to evaluate the quality of weight management apps using comprehensive quality assessment criteria. By doing so, the information quality (RQ1) and system quality (RQ2) were determined, and relationships between these elements, user ratings, and app downloads (RQ3) were examined. Methods - A systematic search in the US App Store using search terms related to weight management was performed. System quality was assessed using the Mobile App Rating Scale (MARS) and rated on a 5-point scale. The Taxonomy of Behavior Change Techniques (BCTs) was used to determine their presence or absence. A second reviewer coded 50% of the apps to account for interrater reliability. The descriptive and inferential statistical data analyses were carried out with SPSS. Results - A sample of N = 38 apps was deemed eligible for this review. On average, 9.6 BCTs were identified per app (range: 3-19). The most frequently used BCTs were Provide instructions (87%) and Prompt self-monitoring (87%). The MARS overall quality scores indicated moderate system quality (M = 3.48; SD .61). Functionality was the highest-scoring MARS domain (M = 3.52; SD .68), while Aesthetics (M = 3.40; SD .84) scored the lowest. Significant positive correlations were identified between the overall MARS score, the number of BCTs, and app downloads. Conclusion - Establishing a standardized framework for quality evaluation would increase the comparability of assessments and the significance for users. Based on the present findings, future app development should involve more health professionals, integrate more evidence- based content, and incorporate more effective BCTs for weight management.