The Water app lets users choose between bottled water and tap water.
Users can then pay to buy bottled water, tap water or both.
The app was launched in July 2018 and has received over 3 million downloads in its first six months.
The Irish Water chief executive, Patrick O’Connell, told the broadcaster RTÉ’s Morning Ireland that he is happy with the app and that the company is looking to develop new ones.
“We’re working on a water app in Ireland and that is a very exciting project,” he said.
“It’s a really exciting project for us.”
Water users can purchase bottled water at Irish Water supermarkets or in other stores, tap tap water at tap-operated restaurants and online, or buy tap water through their mobile phone.
The company is currently testing its app on a number of cities in Ireland, including Dublin, Limerick and Cork.
The water app also allows users to make purchases online and via their mobile phones, including from the Irish Water mobile app, which was launched at the end of June.
The latest version of the app also supports the Apple Watch.
The iOS version is available from Apple’s App Store and the Android version is already available for download on Google Play.
Water has been a favourite among people in the Irish diaspora and the company was one of the first Irish companies to accept the Apple Watches.
The Water company says it has over 4,000 employees worldwide, with a workforce of over 5,000 people in Ireland.