MIT App Inventor is a no-code app development platform that lets you develop applications for Android phones without any prior experience of coding using a web browser. You can test your app on your Android phone or on the emulator. Also, it stores your projects to have a track of them. You can sign-up on App Inventor Website and can start building the app from its drag and drop feature. It has also some detailed tutorials to help you in getting started.
The ability to code at an early age will help your kid to build a career in the STEAM industry and will develop a problem-solving and creative mindset. Even, if you are not looking for STEAM for your kid, a fundamental knowledge of computer science and programming will help your kid in every virtual and technical aspect of their future.