Concerns about his partner’s chest pains four years ago led Auckland-based software developer John Ballinger to buy a microphone and record and analyse her heartbeat.
Those chest pains turned out to be just muscle spasms, but last week the concept led Ballinger to success in Apple’s iPhone AppStore, with a heartbeat monitoring application in the Top 100.
Heart Monitor hit the store last week and almost immediately soared into the 100, reaching 90th place in terms of sales and downloads on Wednesday. That was driven by a video demonstration Ballinger put on the video sharing site Vimeo that immediately went viral, being embedded in blogs and other websites around the world, including high-profile tech sites such as Gizmodo.
As of last week the video had been viewed 1.5 million times.
Ballinger’s success follows that of Wellington game developer David Frampton, who struck iPhone gold with a helicopter game called Chopper which was achieving 500 downloads a day in August and is still in the Top 100.
Third-party developers selling applications on the AppStore get 70% of the sale price of their software.
Despite releasing the application with a warning that it should not be used as a medical device, Ballinger has received rave reviews from people who need to monitor their hearts for health reasons. One comment on the Vimeo post from “Lia” says: “I have infrequent episodes of a-fib. This app caught my heart rate going crazy. I will finally be able to show my doctor. Thanks so much!”
The iPhone app, which sells for US$4.99, has the potential to eliminate the need to use attached electrodes to monitor heart beat as it simply requires the device’s in-built microphone or a remote microphone to be placed over the heart to conduct a reading.
Ballinger says some people have tried to use it for fitness training, but it isn’t suited for that, except to take readings of the resting heart-rate and that immediately after training.
He says making the Top 100 in the store is a big boost for sales, but the top 50 and 25 boosts that even more.
Developing the application may have cost up to $45,000 in time and investment, he says. The biggest challenge was in writing the detection algorithm, which took 20 days and 15 different approaches.
“It could still be refined,” he says. “The next step is to get more sample data — people can submit their heart rates — and use that for fitness testing of the algorithms.”
Heart Monitor is not Ballinger’s first iPhone application. He developed one for the first generation iPhone, possibly the first to arrive in New Zealand, but it was only a proof of concept. He has another application, a mortgage calculator, in the AppStore but considers that trivial compared with Heart Monitor.
Ballinger says it is important to balance production time on an application with the need to release it.
“You can’t release substandard software if you want to make an impact,” he says. He advises other developers to keep their applications original and “don’t do what Apple is doing”, to get it accepted by the AppStore.