Touch-screen tablets are used in the classroom for assessment. Little is known about the psychometric properties of tablet-based assessments. This study examined the validity and reliability of an expressive and receptive assessment app designed to measure literacy skills. Children (N = 45; 3-5 years) completed the app assessments for alphabet and word skills using a tablet. Children (n = 15) were posttested 1 to 2 weeks later to check test score stability. The tablet measures showed good internal consistency (all a > 0.90) and test-retest reliability (intraclass correlation coefficient [ICC] range = 0.87 to 0.98). Agreement between scores for the tablet- and paper-based tests was also high (ICC range = 0.91 to 0.98). This indicates that expressive and receptive tablet tests provide valid and reliable measures.