Over half of educational apps on mobile-app markets are for preschoolers, but little research has examined whether the designs of preschool apps are truly educational. Preschoolers process information differently from older learners (i.e., shorter attention spans), so app designs should be guided by developmental science. This content analysis of popular Apple and Android math and literacy preschool apps uses a developmental framework to code and analyze apps' educational features. Findings show a wide variety of features apps used. However, few provided developmentally appropriate guidance, like scaffolded feedback. This study offers insights for improving apps to meaningfully teach preschoolers.