I still don't know a lot about it, but I signed up, thanks mostly to the education and outreach of 
Hive account@taskmaster4450. Manna is advocating for a cryptocurrency of universal basic income (UBI) for all. If just 10% of Steemians sign-up, it would be a huge boost.
Hive account@scottsantens has also been a big advocate and educator on UBI here on Steemit.
... i also just noticed a new steem account for 
Hive account@mannacurrency as well
If you sign-up you can use my referral link, it gives you a bonus as well as myself:
https://www.mannabase.com/?ref=8a47a6b84e
sign-up today and check it out
peace 
Hive account@clumsysilverdad
