>>Refox is just one of several decompilers. AFAIK, you can't protect against all of them.
>>
>>>How to protect application from decompilation using ReFox,
>>>preferably for free ?
>>>
>>>Is it possible to apply some code to application which prevents its
>>>decompilation using Refox 11 ?
>
>When Refox originally was released it was controversial; to appeal to developers they do indeed provide a mechanism to protecting against themselves. They call it branding. However you have to own refox to use this ability.

...and the branding can be defeated by hacking the refox.exe so it makes it kind of useless.