It sounds like you're looking for (The King of Fighters custom Mugen games on Android) and the phrase "%C3%ADtem" seems like a URL-encoded or typo version of the word "item" (maybe "ítem" in Spanish/Portuguese).
🔽
Busca la versión más reciente del Mugen Android APK (ej. Mugen_Anime_Fight_v7.apk ) en fuentes confiables. kof mugen para android %C3%ADtem