Do you want to keep your resolution? These apps can help.

Here’s what you need to know before downloading.

In terms of price and privacy, Crunchy Bagel developer Streak is the best of the habit-tracking apps. Streaks is a simple habit tracker where you can log your behavior and see your progress over days, weeks or months.

The only fee is $4.99 upfront, and the setup process is quick and minimal.

Best of all, Streaks says it doesn’t share data with sketchy third parties.

Johnny Lin, founder of anti-tracking firm Lockdown Privacy, said that Streaks not only doesn’t send data to advertising companies, it also doesn’t regularly collect data unless you turn on iCloud backups in the app’s settings.

For an easy-to-use habit tracker, try Strides from developer Goals LLC. The interface is limited but clear, and for $29.99 a year you can add more habits and see progress reports.

If you stay on the app’s free tier and avoid creating an account, the company says it stores the data on your device. (This is good for privacy as the data doesn’t end up in the cloud.)

If you’re looking for a sobriety tracking app, choose I Am Sober, which costs $39.99 per year. Unlike some of its competitors, I Am Sober does not collect your location.

It also says it doesn’t share data with advertising or marketing companies. (However, it uses Google for analytics, though CEO Andrew Murray said the company is working to remove Google tools from the app entirely.)

So can these apps really help you break old habits or start new ones?

Tracking behavior helps break and build habits, said Dana Litt, associate professor of health behavior at the University of North Texas.

However, research into the effectiveness of app-based tools is still ongoing.

However, some of these apps go beyond simple habit logging.

Reframe ($119.99 a year) from developer Glucobit offers educational modules and homework for people who want to reduce or eliminate their alcohol consumption.

The Fabulous app ($59.99/year) also offers learning modules for “addiction management.”

But be careful.

Both apps have relatively permissive privacy policies, and many people with addiction need individualized treatment in a clinical setting.

Fabulous co-founder and CEO Sami Ben Hassine said the app isn’t a substitute for counseling, but it can help people grow, measure their progress and regulate their emotions.

If you’re evaluating habitus apps on your own, remember that a habitus app probably doesn’t need your location and can’t ask for more data than it needs.