We present a system designed for assisting people in obtaining healthier lifestyle. The system includes a monitoring device worn on the chest and a web portal that visualizes the measured parameters and provides the user motivating tips for healthier lifestyles. The monitored parameters include heart rate, step count, calorie consumption, activity level, heart rate variability and sleep quality. A unique feature of the system is that the communication from the wearable unit to the backend server is arranged via direct mobile network connection, thus avoiding the need for a separate gateway device. The measured data can be viewed with a web browser user interface. We evaluated the beat-to-beat heart rate estimation performance with ten subjects in a controlled exercise protocol and with three subjects in 24-h free-living conditions. The average mean absolute error of the R-R interval estimation was 8.0 ms and 6.4 ms in the two test scenarios, respectively and the corresponding coverages of the obtained R-R intervals 76% and 94%.