You may want to spend less time on sites like Facebook and YouTube, but actually doing it can sometimes be a bit of a challenge. HabitLab is an open-source project from Stanford that attempts to make cutting back on habit-forming sites a little bit easier.
How it does that is a bit unique. Rather than simply blocking the sites you want to stay away from, the Chrome extension uses tools like news feed blockers and comment hiders to help you cut back.
To use it, you first have to tell it what you want to cut back on. You can add any site or service you want, but out of the box it's built to support things like Gmail, Netflix, YouTube and Reddit. Whenever you visit a site you've told the extension you want to cut back on, it will use artificial intelligence to choose an intervention to help cut back on the time you spend there.
For instance, when you visit Facebook it might hide the comments on your friend's posts. On YouTube, it might pause a video and suggest you do something different.
Over time it learns what sorts of interventions seem to work best for you, and it focuses on those going forward. It's not preventing you from visiting or using those sites, but it is forcing you to be more mindful of the time you spend on them.
Also, since its a research project from Stanford, you're also agreeing to give up a bit of privacy when you use it. Anonymized data about the effects on the interventions on your browsing is routinely sent to the folks that created the extension. You can; however, opt-out of that when you set the extension up, as well as down the line, but it's something to be mindful of.