Brook Framework

https://github.com/risoflora/brookframework

https://wiki.freepascal.org/Brook_for_Free_Pascal

https://www.android-ide.com/

 I suggest you learn the Delphi Programming Language and here is the three main reasons why I think a teen should learn Delphi:

• You can make native cross-platform apps/games for Windows, iOS, MacOS, Android and Linux.
• The language is easy to learn and very powerful.
• Delphi is top 10 in the Tiobe Index

So where can you start? Here is a list of links:

• Official Embarcadero Delphi Website
• Free Embarcadero Delphi Starter Edition
• Free Lazarus IDE
• Free Delphi Training Videos
• Delphi Programming Helper (App)
• DelphiBasics (Website)