A team of researchers and engineers have developed a new application for smartphones that could allow doctors using their mobiles to monitor patients' hearts. The i-Stethoscope uses sensors built-in the phone to check a person's heart. Data can be collected and shared with ease. But according to doctors, there are still some things the app cannot do, since it cannot substitute for the doctor-patient relationship. Eko Devices, the Berkeley, California-based company that developed the smartphone app, has received FDA 510(k) clearance for the companion smartphone app and for its smartphone-enabled stethoscope, called Eko Core.