When you gotta go, you gotta go -- until all the cubicles are full and there's a snaking line waiting.

A Japanese company has the perfect solution: an app that shows the nearest vacant toilet.

According to telecommunications giant KDDI, the app will predict if toilets are in use by using sensors installed on stall doors to determine whether they are open or closed.

App users will then receive real-time updates on how many cubicles are available in their area.

"People often waste time by looking around for an available toilet on various floors or by waiting until one becomes available," KDDI spokesman Daisuke Maruo told the Japan Times.

"We believe this service will help people waste less time."

The sensors will also notify an administrator if a toilet stall is occupied for more than 30 minutes, which is meant to warn against potential accidents -- but also means you'll be busted for catching a snooze during work hours.

KDDI says that the service will first be made available across office buildings. If proven successful, it will also be rolled out in places like sports stadiums, train stations and malls.

The company will start selling the service to facility owners from March.

But that's not all. KDDI also wants to start a service that analyses the amount of water needed to flush toilets.

An internet-connected valve will analyse the amount of time the person was in the cubicle and based on that, predict how much water needs to be dispensed.

This is the world we live in.