Need a native android developer to upgrade my application

I have an android application, now I want to add some new features in my application. I will give design to the developer and developer has to develop the app as I need. After the job is done the developer has to provide me the source code also. I mention my application link below.

App link : https://play.google.com/store/apps/details?id=com.grapplications.statussaver