London, Aug 31: The iPhone could replace the stethoscope as millions of doctors worldwide are signing up for a free application created by a University College London researcher. Peter Bentley invented the iStethoscope application which monitors heartbeat through sensors in the phone as just a bit of fun. But it took off and now 500 applications are being downloaded everyday after a free version was introduced last week, reports the Telegraph. “Everybody is very excited about the potential of the adoption of mobile phone technology into the medical workplace, and rightly so,” said Bentley. “Smartphones are incredibly powerful devices packed full of sensors, cameras, high-quality microphones with amazing displays,” he said. In the furture it could be possible for people to conduct their own ultrasounds or monitor blood pressure through smartphones.