The co-creators of Instagram, Kevin Systrom and Mike Krieger, just launched their first new project since leaving Facebook: Rt.live.

Rt.live is a data visualization website aimed directly at combating the coronavirus pandemic. It tracks the spread of the virus on a state-by-state basis.

"We believe Rt — the effective infection rate — is one of the best ways to understand how COVID is spreading," Krieger told TechCrunch. "We'd been talking about ways of working together and this came out of that."

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After creating Instagram, selling it to Facebook in 2012 for $1 billion, and walking away from the company in 2018, Kevin Systrom and Mike Krieger have yet to launch their next big thing.

But this week, the duo behind Instagram launched their first new project in years: It's called rt.live, and it's intended to help fight the coronavirus pandemic.

The "rt" in the project's name is a reference R t , the "basic reproduction score" used in epidemiology to track whether a disease will spread. The site pulls in data from The COVID Tracking Project, and offers an R t score for each of the 50 US states. (You may be familiar with R 0 or "R nought," another measure of disease spread — the main difference between R t and R 0 is that R t is dynamic. R 0 measures how far a disease could potentially spread; R t tracks how fast a disease is spreading at the current moment in time.)

"Values over 1.0 mean we should expect more cases in that area," the site's description says, "values under 1.0 mean we should expect fewer."

Though Ohio has far fewer cases of coronavirus than New York, the rate at which it is spreading in Ohio is far faster at this point in time. RT.live

The site enables filtering based on geography, and by states that enacted shelter in place orders versus those that didn't.

The point of the site, Krieger told TechCrunch, is to assist state governments with data that can help them re-open.

"As states decide whether and how to open back up, they'll have to manage their infection rate carefully," he said. "And we hope dashboards like rt.live will be helpful in doing so."

You can check out rt.live right here.