It depends on what you mean by real world applications, but Chibi has many features including threads, networking and an FFI suitable for any application. R7RS large will have even more libraries. It will be complete when it's completed, but many of the individual libraries will be usable before then.

Thanks for answer, I want to make a simple game in scheme, so I am considering chibi, maybe I need to try somehow to add opengl binding. I know there is other implementations but I want to try chibi (r7rs) :)