Last year we set out to create an ultra fast and extremely cheap Feature Flagging solution, DevCycle [1]
We pulled it off, and it has been growing and working great for those using it.
Hoping to expand it to be a deeper part of the development lifecycle, and having a deeper integrations with things such as datadog.
Depends on what devs are looking for really, but we have a base direction to start with and are going strong.