Commonly, navigation uses GPS signals to determine location. In addition, GPS data can be collected over time to determine path taken. In spite of the ubiquity of GPS signals on the earth's surface, there are certain locations where GPS signals are not available, such as inside a buildings or tunnels. Therefore, to determine accurate positioning in areas where GPS signals are unavailable, an Inertial Measurement Unit (IMU) can be used in conjunction with GPS data. Modern IMUs are small enough to be contained in MEMS chips, including in smartphone devices such as iPhones. This work studies the integration between GPS signal and the collected data from smartphones' MEMS sensors. It also investigates the possibility of using the integrated GPS/MEMS information to estimate route when the GPS signal is missing. We propose estimating the missing GPS signal by sensor integration of smartphone data. This research work would enhance the GPS navigation to determine exact positions even in case of signal failures. Modern IMUs are expensive, and this research shows that GPS/IMU integration can be accomplished with off-the-shelf navigational components. This paper proposes a novel technique for estimating the missing GPS route by integrating data from the sensors available in modern smartphones.