Since its launch in December, NHS Health Help Now has clocked up 4,023 hits in Kent with 2,715 visitors.
However, only 55 came from Dartford and 39 from Gravesend.
Health bosses have now launched a four-week marketing campaign to promote the app, which provides details on the best place to go for medical advice or treatment at any time of day or night.
Posters will appear on billboards and bus shelters, and information packs have been sent to NHS trusts, GP surgeries, schools, colleges, universities and businesses, including hairdressing salons and takeaway outlets.
Health professionals have also been demonstrating the benefits of the app to shoppers in the St George’s Centre in Gravesend.
The NHS Health Help Now app is demonstrated by Joe Linnell (centre) to Ghazi Jan (left) and Priya Ponton with her four-year-old daughter, Georgia
Dad-to-be Ghazi Jan said he was “desperate” to kick his 80-a-day smoking habit. “I am 31 and have been smoking since I was 16 after breaking a leg playing cricket.
“I used the app to find my nearest stop-smoking clinic.”
Priya Ponton added the app to her phone. She said: “My husband has been very ill. He had a heart attack last year and has a number of long-term health conditions.”
Health Help Now is believed to be the first app of its kind in the UK and aims to stop patients using the county’s A&Es, including Darent Valley in Dartford, needlessly.
On average, 260 people attend Darent Valley’s emergency department every day, but only 28% of patients are admitted.
It costs the NHS £110 for every A&E attendance, compared with £62 for every visit to a minor injury unit and £36 for each GP visit.
Dr Bhaskar Bora is chairman of NHS Dartford, Gravesham and Swanley Clinical Commissioning Group, which is responsible for managing the £278 million budget for its 249,000 patients.
He said: “Many people believe they will be seen quicker and by specialists at A&E, but unless it is a life-threatening emergency this is seldom the case.
“People with minor injuries, flu and ailments which can be treated at home, by a GP or a pharmacist should leave A&E for those who really need it.”