Preterm labor is one of the major public health problems in the developing countries, where accessibility to health facilities is low in some areas. Home monitoring devices could be good options in this situations. Therefore, we developed a tool for early detection of contractions. The type of signal, artifacts removing way, a method for sending signals safely, detecting abnormal contractions method, and evaluation methods were determined. EHG signals were applied to send contractions to mobile application. Alarms were displayed if abnormal contraction is detected. Relative Error and Co-efficient of variation were calculated for evaluation of accuracy and repeatability of device, respectively, which were acceptable. This portable, low weight, low cost and easy to use uterine contraction-monitoring device could be used in urban and rural health centers, at home and by pregnant women who are living in hard-to-reach places. This may help early awareness and take action to prevent premature birth.