I'm amazed by how much you've achieved with this project! I thought it was 2 months worth of work until I looked at your blog, but even to have managed this in spare time over a couple of years is amazing.
The only thing I can think to suggest by way of improvement is some fairly prominent examples of the kinds of segmentation you can do with Flipt.
Do you see this being used for A/B testing as part of a pro version?