What makes it better

There are two main kinds of habit trackers:

Paper

Usually a paper-based habit tracker is built as a table. Maybe you have a column for every day of the month, and then you have a row for every habit that you're trying to develop. Do the thing on a given day — say, meditate — and then check it off.

Software

Of course there's an app for that. You set yourself up with whatever activities you want to do, and tick them off. Maybe with a home screen widget, or an app on your phone, or even your watch.

Not Good Enough

While the traditional paper and software habit trackers are well-intentioned, they're just not good enough:

Issues with paper-based habit trackers

It's a piece of paper you have to carry around. It can get crumpled or wet.
It's not very private. Habits are a personal thing, and it's easy to look over your shoulder and see what you've marked off.
They assume a fixed timespan. Typically it's a month, and the idea is that you'll do each action once per day.

Issues with software-based habit trackers

These tend to get bloated and complicated.
Every time you want to check off a habit, you have to use your device. There's a reason "spend more time on my phone" is not a popular New Year's resolution.
Privacy is an issue, again. Not only is it easy to look over your shoulder, there's always analytics to consider. Does the developer know what habits you're tracking? Are you sure they don't?
While some of these are a single purchase, other apps are subscription-based and get expensive over time.

Issues shared by both types

Both types of trackers have privacy issues. They share some other flaws, too:

They're typically built for tracking multiple habits. But if you're trying to work on something, you need focus. You don't want to work on five or ten habits at once, but this is just what their design encourages.
They emphasize failure. Seinfeld popularized a concept called "don't break the chain". Write something each and every day, mark it off — after a month, you "can't stop" because it'll "break the chain". But if you do happen to stop for a day, it's very visible, and it feels like failure. That is not the mindset to be building a new identity from.