If you're talking about "next technology-first unicorn that's going to make it big in the next 10 years", good luck. That's what everyone and their mother has been looking for in the past 10 years. These tend to get eaten up by an existing FAANG if it looks like there's a good fit.
There are also plenty of other companies that have FAANG-levels of name recognition but probably won't get to the same size. These are your VC-driven, trying-to-dominate-a-market-but-it's-hard (ex. Ubers/Lyfts, bikeshare-of-the-week) and doing-well-in-a-niche-but-not-as-large (ex. Square) companies.
https://medium.com/chingu/africans-can-build-billion-dollar-...
Virtual Reality seems like a safer bet.
Out of curiosity, can you explain why you think so? I'd think block chain has the bigger potential, but I don't keep myself up to date on VR.
docker
twilio
X github (gone)