Built a small resume app using Android Studio and Kotlin.
In terms of Kotlin, the course taught my the basics the language (variables / loops / functions / lists / arrays / classes etc.).
In terms of the app, I learned how to use buttons to move between activities, and link to the phone / email clients on Andriod devices.
All learning and guidance from 'The Complete Kotlin Developer Course' by Nick Walter and Rob Percival. Link below.
https://www.udemy.com/course/the-complete-kotlin-developer-course-java/