Backstory: I started following Sean Wes a few months ago, because I enjoy his writing. Awhile ago, he published a long-form article about a "Five Habit Tracker." The Five Habit Tracker is a simple system for tracking your habits on a piece of paper. You can check it out here: https://seanwes.com/2018/five-habit-tracker-free-printable-pdf/
The Idea: I like the idea of a PDF where you can create and track habits. Ideally, I would prefer a simple habit tracker in the form of a mobile app.
Deep Dive: You can choose to make your own version of a habit tracker, or make one just like Sean's. If you make Sean's, I'd recommend reaching out to him and asking if he's okay with it. You never know, a cool partnership could develop from something like this.
Validation: Current habit trackers are built to be way too complex. We need a simple habit tracker like Seans. Put it on mobile.
Monetization: You could charge a monthly subscription, or a one-time fee.