I did go to
http://btcgpu.com/ then I saw the form with input BTC address.
There was been an link on the site
https://MYBTGWALLET.COMI remember MyEtherWallet so i go there and see web-wallet.
Addresses is beginning from G and A symbol. Compressed and uncompressed.
I did download zip and see public key version bytes 0x27 (G) and 0x17 (A) for new SegWit addresses.
So I did add this both to previous modified brainwallet (see my previous posts).
Compressed and uncompressed keys and addresses is available there.
Also I did add supporting for Segwit addresses and simply JS file encryptor in browser.
You all can download it and test here:
http://rgho.st/7vlks4RghJust press button "Cкaчaть" to get zip,
unzip it
and open index.html in the tab of your browser.
Now BTG you can select there and generate addresses for mining. Open source.