Gas-consumed urban transportation causes the problems of environment pollution and traffic congestion.Bicycling is an alternative transportation way for short-distance movement, which is a green and healthy style. Some modern cities are building Public Bicycle Sharing System (PBSS), so that inhabitants and tourists can temporarily use bicycles anywhere in the city. In this paper, GreenBicycling, a smartphone-based Public Bicycle Sharing System for healthy life is developed. GreenBicycling aims to improve the user experience and encourage cyclist to use BSS. It allows cyclist to query not only the current information of rental spots, but also the forecast state. To achieve this goal, an improved back propagation network prediction model is proposed. In addition, a quantitative measurement of calorie consumption in a riding trip is introduced into GreenBicycling, so that the cyclist could get intuitive understanding of how much calorie reduction from the riding. A simplified version of the GreenBicycling APP has been released in the Windows Phone Market.