we need to modify my agri eccomerce android app

i want to modify my android application developed in java and add new features, new apis,
this is ,link of my application : https://play.google.com/store/apps/details?id=com.globalfarmer.agrifarm

like this
https://play.google.com/store/search?q=agrostar&c=apps
https://play.google.com/store/apps/details?id=com.kisanwala