Shareable checklists - is it worth building?

Hi everyone. This is my first post here and I'd like to validate the idea I'm going to work on.

The basic idea is simple - I'm going to sell checklists.

There are tonnes of services offering printable checklists. It is really that simple - pay 2-5$, get image, print it, and make marks on it. Eventually, all such services do is just selling pictures. Despite the simplicity, they making money.

I'm going to hop into this niche but what I'm going to do is real online service around checklists. The idea is that you don't need to print it (although you can). You can make marks online. Also, you can share your checklists with others. For some communities, the aspect of competition may be important. They can share checklists with each other and then such checklists would serve as achievements tracking.

Also, my checklists may not just be a collection of boolean values. It may be a collection of numerical values which means that with proper visualization I would be able to generate colorful graphs. A closer example is github contribution graph (https://www.google.com/search?q=github+contribution+graph&sxsrf=ALeKk01OV4tUTY7ajskwNtjosAi6Ok1imw:1616091514029&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiMs_iEurrvAhWO4IUKHQkOAP8Q_AUoAXoECAEQAw&biw=2556&bih=932)

Also checklists builders. But I have no idea how to charge for such functionality.

Few use cases that came to mind :

• I feel like I've been drinking too much lately. I do not fully understand the extent of the problem and want to reduce my alcohol consumption. However, each time there is a new and new reason to drink. I am creating a 360 days checklist where I mark the days I drank alcohol. Over time, I begin to see the real picture and this stimulates
• I would like to improve my physical condition and I am going to train 6 days a week. But I'm too lazy to ever move my ass. I create a checklist and mark the days when I trained.

How do you think this worse building? Would you pay for this?

UP.
Made simple landing page with ability to subscribe for when service would be ready - http://checkie.me/

UP.
Made some progress so now I able to show a screenshot that illustrates the whole idea of project: http://checkie.me/checkiescreenshots1.png