AI's promise to become embedded in every aspect of modern life is quickly becoming a reality. However, a significant gap emerges in educational resources tailored for adolescents. This void often cultivates misconceptions about AI's capabilities and potential risks. To close this gap, we present SMaILE-App, a novel educational cross-platform app designed to foster AI literacy among individuals aged 10 to 18. While inclusive, the app design is purposely biased towards rectifying the gender gap in STEM. Applying a constructionist educational framework, SMaILE-App promotes learning AI fundamentals through inter-active gameplay, merging entertainment with personalized knowledge acquisition. SMaILE-App comprises a suite of minigames in an engaging narrative, each focusing on a different AI concept, as well as interactive creational and instructive modules. SMaILE- App rests on two key ideas: AI is not a singular, all-encompassing term but a spectrum of methodologies, each with its nuances, and AI is not without its limitations.