App updates and building a website

What I am looking for is changing certain features to an already existing app that is ready for beta testing  Android and IOS platform 1. Switching the payment gateway from paypal to stripe  2. Changing the google map API to a random estimated distance from exact user location. 3. Improve the search feature to look up all ads posted in the app not just the categories page 4. Create a feature for 30/60/90 day free trial for posting intangible ads 5. Create an in-house messaging system to allow users to communicate anonymously 6. Automatic filter of ads based on the users location Website Admin Page 1. Adding excel download to the products sold page on the admin website.  2. Reconfiguring the banner page to allow multiple banners to show.  3. Notifications feature should alert users when they receive new notifications. The admin should be able to send individual notifications to individual users Landing website 1. Designing a website for the app that mirrors the performance of the mobile app. Overall Service Support 1. Ensuring all technical questions from IOS and Android Stores are addressed and full testing until go live