if you got a new contact in your address book you might want to send him the first whatsapp message 30s later, so it better checks for new contacts all the time

if you got a new contact in your address book you might want to send him the first whatsapp message 30s later, so it better checks for new contacts all the time... If there is no listener for of some kind in the api (android system telling all apps who want to know once there is an update), it will have to ask the system over and over again.