The mobile apps were developed by a team a team from Ethics Advanced Technology Limited (EATL). After developing the apps study team did the filed test and piloting in other than project areas. After receiving the feedback, study team tried to make the easiest apps. The SMS messages were developed by a team comprising of general physicians, immunization expert, family planning expert, health systems expert, health care provider, GoB officials and non government officials. After developing the SMS messages in Bengali, study team sent these messages to several individuals in the pre-test stage including persons who can only read SMS and have no formal education qualifications. After receiving the feedback, study team tried to make the contents of the SMS suitable for the general population. Investigators will ensure that all our participants in the study can read the SMS messages by themselves or someone in the family who can describe the messages to them if they do not understand.