Im trying to set up port forwarding with ktorrent but i don't know what to put in the application field (ktorrent doesn't fit), anyone know what i should enter?

I guess it is enough to just put a name in it so you could remember the rule you made by yourself.

the name u put in is irrelevant. your router is forwarding to the computer, not the application. to answer your question, ktorr works just fine in the application field.