He estimated about 75 per cent of the wines in a Countdown supermarket aisle would be covered by the app and said he was being approached by one to two wineries a day.
"The ultimate goal is to allow anyone from the casual drinker to the discerning connoisseur to easily pick the perfect wine for the occasion or their taste," Harper said.
"Up until now, no one has built a mobile application that bridges the gap between the needs of wineries and consumers."
Harper funded the app's development with a personal loan and did all the other work on the project himself.
While the app is free for users, wineries get a six-month trial, after which they are charged a subscription fee to have their wines in the system.
The NZ Wine App is available on Android smartphones, the iPhone and the iPad.