Is there any use case of blackbytes
like where can i sell this blackbytes, unable to find any market of it
http://www.beeb-bot.com/If you know you have blackbytes, then you have a wallet. Trading can done directly within the wallet. Not sure where you were looking, but you should first look around in the wallet itself at the features it has.
About this, is there any particular reason why GBB is not on any exchange? I know this has been asked a gazillion times already but I still wonder, what is it about GBB's anonymity tech that makes it not a good fit for exchanges compared to other anonymous crypto? XMR, for example, is also anonymous but tradeable on Bittrex.