Ch is described as 'C/C++ interpreter and scripting language environment used by teachers, students, engineers and scientists around the world to learn math, numerical computing, C/C++, and write cross-platform code and embedded scripts quickly and efficiently' and is an app in the Development category. There are three alternatives to Ch for Linux, BSD, Mac and Windows. The best alternative is Cling, which is both free and Open Source. Other great apps like Ch are CINT (Free, Open Source) and Interactive GCC (IGCC) (Free, Open Source).
Cling is an interactive C++ interpreter, built on the top of LLVM and Clang libraries. Its advantages over the standard interpreters are that it has command line prompt and uses just-in-time (JIT) compiler for compilation.
CINT is an interpreter for C and C++ code. It is useful e.g. for situations where rapid development is more important than execution time. Using an interpreter the compile and link cycle is dramatically reduced facilitating rapid development.
IGCC is a real-eval-print loop (REPL) simulator for C/C++ programmers. It allows you to type C++ commands which are immediately compiled and executed. Underneath it uses the normal GCC exe for compiling.