Social Media Management App

Hello I run over 10 facebook accounts on facebook marketplace and need to manage all marketplace accounts on one interface,
So what I want to do is have a single app on each phone managing each marketplace account. The app does the following:
- Manage All Ads by reposting any ads that need reposting by 6pm mountain time
- The app will then take all marketplace messages to one app so I can manage all 10 accounts on one phone. So the primary management app will manage all phones but will responds back to each individual recipient to each phone
After all this is setup, would like to be able to install this app on multiple other phones or as many phones as possible managing as many facebook marketplace accounts as possible.
Let me know how much you charge to setup the app to track the standard phones with facebook marketplace accounts and then setup a primary management app to manage all phones.