The app, which is part of the Refill campaign and run by plastic pollution campaign group City to Sea, features more than 25,000 water refill stations nationwide.
The app has been downloaded 260,000 times and is used by 30,000 people on average per month.
At registered Blakemore Retail Spar stores, members of the public are able to ask staff members for free water top ups at foodservice counters.
Blakemore Retail managing director Matt Teague said: “We are delighted to be partnering with City to Sea and their Refill campaign to help promote refillable services at our Spar stores.
“Our customers tell us that they are concerned about their plastic consumption, and so as a business we are committed to implementing changes to help them reduce it.
“This is a great initiative that will enable people to save money and cut down on plastic pollution.”
App users can also register their refills on the platform in order to measure their personal impact.
City to Sea ceo Rebecca Burgess added: “It’s great to see businesses like A.F. Blakemore/Spar getting behind the Refill Revolution as a positive way to help their customers cut down on single-use plastic.
“We hope they can be an inspiration to other convenience stores and we congratulate them for making it easy for their customers to fill their up their reusable water bottles on the go for free.”