I'm an Atlassian engineer & heavy Aerobatic user. It's very nicely integrated with Bitbucket, and has great support for Jekyll, Hugo, and arbitrary npm builds. It also has some advantages over github.io like being able to deploy multiple feature branches from the same repository to separate sites, so you can have separate "staging" and "production" versions.

It is a paid offering, though you get two repositories free, and is very pretty reasonably priced beyond that.