None that I know of except companies solving specific problems for the crytocurrency community. There are lots of companies doing useful things claiming to use

None that I know of except companies solving specific problems for the crytocurrency community. There are lots of companies doing useful things claiming to use blockchain but when you deleve into the details aren't actually using blockchain like GUTS Ticketing https://guts.tickets/ https://guts.tickets/ And there are lots of companies really using blockchain but of no real use like HDAC https://www.hdactech.com/ https://www.hdactech.com/ The intersection of useful and blockchain comprises of virtually no companies.