For now, as an experimental project (please report bugs), we have managed to add Bitcoin support to SteemNova project. If you want to earn extra Bitcoin (except Steem and Hive):
- Sign up for durango.intinte.org
- Connect your SteemNova account with Durango
- Wait for the first payout
- Register on Zapread.com on free time to received funds there

I would like to thank fwtf for writing the tools :)