I learnt C++ , it is used to make program but how it can be used to make apps ?
Hello
You have to decide for which platform you want to make an app i.e Android, iOS, Windows..
Then download instrument for development, typically its IDE ,which contains every thing you need :code editor,profiler ,debugger,tools for uploadingapp to an actual device ,simulator.
You can google ,how to write c++for differentplatform. Download IDE and start.
Good Luck.