Write an Android application

We have a web app called [login to view URL], which has a subscription based payment management system. The web app comes with its native android app. We are looking for some one to help us integrate this already built subscription based payment management system into our android app. The functionality is already built in our web app. We just need to integrate the same into our android app. This is a healthcare web app, where people can go and post a skin problem and get answers about their skin problems from skinexam verified dermatologists. We are now have a feature, where users can submit cases without individually paying as a part of their company plan, they are subscribed to. This feature needs to be tweaked on our android app.