Create a program

is it possible to create in this constructor not a game, but a program, for example, so that my project launches some application or plays a YouTube video

Launch an application → NO
Play a YouTube video → Probably not unless you do something fancy with javascript, you can however open any URL (including youtube) in an external browser on non-ios platforms.

Use custom JavaScript, you can open a url

and whether it is possible to create a browser inside the designer?

hmmmm, i dont know :woman_shrugging:

As in inside the editor? No.

ok thank you very much