App developer Mobikats is celebrating a successful debut on iTunes for the NHS Direct app created for the National Health Service in the UK. As of yesterday morning, the app, which features an interactive symptom checker that allows people to work out if they need to see a doctor, was the top free app on iTunes (as the image reveals), with 82,216 downloads in the space of just a few days.

While the app developer is delighted with the iTunes numbers, however, it admits to being baffled by a massive discrepancy between iOS downloads, and those for the Android version of the app, which at the same point in time, totalled a mere 3,442, or 24x less than the number of iOS downloads.

Mobikats director Phill Hunt cites two reasons for the app’s runaway success on iTunes, compared to Android market. Firstly, he says, Android users are less app-orientated, and secondly, unlike Apple, who featured the app, “it’s difficult to get Google to feature an app”.