C++ or c# for apps

Answer 1

C# is a lot better for making gui apps

Answer 2

It depends on the app and how you want to code. Mobile apps are generally coded in java. Desktop applications are usually coded in C# or C++. It just depends on your needs and platform. It's also preference.

Answer 3

Java or C# are used for make Mobile Apps, with Android Studio and Xamarin respectively
You can make desktop apps with any programming language, if you wanna make GUI's learn about it in your favorite programming language