Extracting wordpress .sql and application

I am a web developer who has been hired to move a wordpress website. The domain is exactly the same. What we don’t know is the username and password to get into the control panel of the current host. Is there a good plug in or back up tool that will just extract the database and the app so we can move it to out server. We have control over the domain DNS and a hosting spot but the previous web developer wont tell us the username and passoword and where the site is being hosted.