Exec Javascript ES9 is an Android app developed by Michael Lauer, available for free in the Education & Reference category. It is a powerful Javascript IDE that allows users to code, execute, and test their programs easily.

With its user-friendly interface, the app provides features such as syntax highlighting, line numbering, and an input form. Users can also save and open files with ease. The app also includes an HTTP(S) client that supports GET, POST, PUT, and HEAD requests, as well as an MQTT(S) client for publish and subscribe.

Exec Javascript ES9 also comes with preloaded samples for users to experiment with and learn from. The app is perfect for anyone who wants to learn and practice Javascript on-the-go.

Overall, Exec Javascript ES9 is a great tool for anyone who needs a Javascript IDE on their Android device. It is easy to use, functional, and provides all the necessary features for coding and testing Javascript programs.