Consumers that want to learn more about their sleep habits and effectively track symptoms associated with inefficient sleep have been offered an application by a leading group of experts on the daily activity. A new product suite designed for Nokia's C7 and Samsung Nexus S phones has been launched in a joint-venture between Swedish-based healthcare technology company Cypak and Meridian Health, a not-for-profit healthcare organisation in New Jersey. The free SleepTrak application works with a wireless-enabled credit card-sized device, which is worn on the upper arm to measure restful sleep. Since launching in May 2011, SleepTrak has addressed the lack of good-quality sleep by providing data to present to physicians, logging stress levels gives extra dimensions to data. Director of iMPak Health Sandra Elliott, who worked with the project, said: "Our research found that people are looking for data to help identify factors that contribute to feelings of poor health, such as a restless night of sleep or high-stress levels. By linking this data to a person's mobile phone we are making the information easily accessible."