I have successfully installed Viber Bada in my Samsung Wave (GT-S8500) without any modification is done. I just downloaded Viber Bada via KIES which selected Samsung Wave 3 category.
After completed downloaded, I am able to find Viber Bada in my Samsung Wave (GT-S8500) from SamsungApps/MyPage/Downloads/ViberBada. Once I have found Viber Bada from the above, I just click “get” and it will automatic downloading and installing in my Wave (GT-S8500. I can send text, photo messages and share locations with other Viber users, anytime, anywhere for free of charge.
However, it is not available for free call feature at this moment. But, I am enjoying use Viber Bada while waiting for free call feature. You may try it out. Thanks !