What I most miss from nullboard is a self-hosted-absurdly-small-single-file PHP backend which adds SQLite support. I can't (== don't want to) rely on LocalStorage.
I'ts on my to-do list, but life always puts aonther thing on top of that :-)
For this to happen the storage "module" needs to be redone and cleaned up, which in turn requires having a couple of free weekends and these are hard to come by.
That said, if you will get to the point of doing anything with an aim of submitting a pull request - do ask me first. Chances are that it will take a very long time to accept the request, because that too requires a weekend to review.
I'ts on my to-do list, but life always puts aonther thing on top of that :-)