WiFi Master Key, an app which lets users crowdsource login credentials for Wi-Fi hotspots, hit more than 800 million total users.

The app has more than 460 million monthly active users and the company says it is expanding its global footprint after “achieving a substantial user base” in China.

In less than seven months since its overseas launch last September, WiFi Master Key has seen rapid growth across 223 countries and regions, it added.

Moving forward, the app maker will continue to focus on providing better free internet services for users worldwide, it said.

Launched in September 2012, WiFi Master Key claims to be “China’s youngest unicorn mobile internet company”, achieving a billion-dollar valuation in 2015, after closing a $52 million Series A funding.

WiFi Master Key was number five on App Annie’s global top Android and iOS apps list for February, after giants WhatsApp, Facebook, Facebook Messenger and Instagram .

“The app has been a scorching success in numerous mature and developing countries, performing particularly well in Brazil and Mexico where it remained in the top 10 by downloads on Google Play from 6 February to 29 February,” the report said.

“Having set up a regional headquarters in Singapore last year, WiFi Master Key is primed for further success in emerging markets where mobile connectivity remains unstable, and sharing apps are wholeheartedly embraced,” App Annie added.

Key features of the app include safe Wi-Fi sharing without revealing shared passwords, an in-built signal detector and a speed tester.