A popular smartphone app purported to accurately measure blood pressure in an instant actually fails to detect high blood pressure in eight out of 10 patients thereby potentially putting users' health at risk an alarming study has found. Although the app called Instant Blood Pressure is no longer available for purchase it was downloaded more than 100000 times and is still functional on phones the researchers said. Because this app does such a terrible job measuring blood pressure it could lead to irreparable harm by masking the true risk of heart attacks and strokes in people who rely on the