My problem with habit-trackers is that they're all the same. All of them basically allow to track only one thing - X times per 1 day. That's very rigid and goes against my instinct to ease into new things.
I wanted something that's flexible, self-sustainable, and wouldn't require a lot of maintenance.
After a bit of tinkering I came up with something novel - adjustable habit frequencies. And made all the custom github/anki-style heatmaps with all that functionality on top, meaning stuff like heatmaps for once-in-three-days habits.
It's hard to put into words, as it's very visual, so here's the landing: https://neohabit.org/ (might be a bit slow as it's deployed with github-pages)
And a demo: https://neohabit.org/projects