Looks like a scam / hack or something it says "Funding: $30,000,000 USD investment on standard YC terms" which is weird first and second the Github mail app doing this has been developed by a Github account that is 3 days old.
They tag 25-30 GH accounts in each issue, looking for applications. Apparently they ran out of candidates.
Related [1] - 50 points - 17 hours ago - 29 Comments
[1] - https://news.ycombinator.com/item?id=45352610