A French app that shares your location just got backed by one of Twitter's earliest investors

Location sharing apps have always bordered on the creepy, but investors are starting to bet that an app out of France might be the one to finally make it cool.

Benchmark's Peter Fenton is leading a big funding round in Zenly, a popular app in Europe that lets friends share their locations with each other, according to multiple sources.

One source pegged the funding at roughly $20 million. This is following a $11.2 million funding round announced in May.

Fenton, an early investor in Twitter and other internet hits such as Yelp, would represent the startup's first marquee-name Silicon Valley backer.

The app has taken off in Europe where teenagers have latched onto knowing who is doing what and where they are that minute. It preys a little bit on FOMO - or fear of missing out - but people keep coming back to make sure they're not the ones missing out on a hot party or event with their friends.

In May, the company told TechCrunch it was close to hitting 1 million registered users and had around 340,000 monthly active users. Data from Apptopia through this September shows it now has 1.7 million downloads on iOS and Android devices.

Still, nearly half of the downloads are in Europe.

One reason Zenly stands a chance compared to other location-tracking apps is that it doesn't constantly monitor your location and kill your battery as a result. Instead, the app only pings your phone's location when a friend opens it up to look for you so it's not constantly running in the background.

That solves the technology barrier of location-tracking apps, but Zenly still needs to work on building it into a social network that doesn't turn creepy.

For instance, most people don't use Apple's "Find my Friends" feature or are even hesitant to let Facebook let people know when they're around - and those are two apps that many already have installed. Zenly though is already spreading through word of mouth, and is rumored to be growing at 8% week-over-week.

Both Fenton and Zenly did not respond to multiple requests for comment.

Zenly still has a long way to go to make sure it's used less for creeping on people and more for fun, but it's already proving itself to be an early success - and attracting the investor cash as a result.