Shameless plug for https://heyhabit.com (I'm the dev). It's meant to be used as a chrome extension that takes over the new tab in Chrome, but you can try it from the website. I've been using it for ~2 years now and it works really well off and on. I've discovered that it's really helpful for getting me back on track when I fall off the horse. Because the calendar maintains what a "successful" week looks like for me, it eliminates some of the mental energy required to regroup.
