Kotlin

Kotlin, learned through Google's Android Basics with Compose course The Android counterpart to Swift, and the language to learn if the phone in your pocket runs Android. Android development has been Kotlin-first since 2019 and over 95% of the top thousand Android apps use it, so this is the mainstream route rather than a side road. Google's self-paced Android Basics with Compose course starts from introductory programming concepts in Kotlin and asks only for basic computer and math skills and a computer that can run Android Studio. The catch is that Android Studio is a heavyweight professional tool, so expect more setup before your first app than with Swift Playgrounds.