BEIJING, March 1 (Xinhua) -- Locating public toilets can be frustrating for tourists, but a mobile app is helping tourists find nearby facilities with just a tap on a screen.

Launched at the start of this year, the tourist toilets navigation system developed by the National Tourism Administration (NTA) and online mapping service provider amap.com has received 15 million visits from mobile users across China.

By tapping a button on the Amap smartphone app, users can see all public toilets within 2 km of their location and receive the recommended shortest routes.

The service includes location and direction information for nearly 500,000 public toilets, covering all 5A and 4A level scenic spots in China. The goal is to include all scenic spots, cover other public facilities such as railway stations and restaurants, and reach as many as 700 million people.

The app is the latest measure to help propel the "toilet revolution."

In 2015, the NTA began a three-year campaign to install new toilets and upgrade existing ones in scenic areas to provide sufficient clean, free, well-managed facilities for the public. The effort will continue as plans have been announced to build and expand 24,000 public bathrooms in 2018 and 64,000 in the next three years.

The NTA and amap.com also published an index that measures the accessibility of public toilets in 100 cities based on figures including total and per capita toilet numbers.

Southern China metropolis Shenzhen received the highest rating, followed by Foshan in Guangdong Province and Shanghai, with Beijing also in the top ten.