Android CRM Development from Scratch PHP Codeigniter

Hi, I need to build CRM to manager Sales Team for both Inbound and Outbound Calls. The sales executives will have the app installed in their android phones. Things to Syncronize from Android App: 1) Call history 2) Contacts(we can use Google Contacts API for this) 3) SMS 4) Whatsapp Calls & Messages 1) person ---all details of a person ---all data that is synced from the sales executive mobile will be linked with person id, and create a timeline of it 2) company ---company profile ---linked with 1 or multiple people 3) Lead ---company with 1 or multiple contacts will be a lead ---sales executive will send proposal from his web based login 4) Followups ---in followups sales user will see all the followups he needs to do ---followup will be added by senior sales executive ---when a fresh lead comes it'll show show in lead and followups also ---every day, unconverted leads will be showing in followup section ---when a sales executive mark as followup done, then it'll ask for comment. 5) Products/Services ---add, edit, view, manage products by admin ---product form will contain its MRP, Selling price etc fields --- 6) Proposal / Quotation ---sales executive will send quotation from this section ---he'll select all the products customer is interested in and enter the custom price if any discount ---discount limit will be set by senior ---if discount is beyond limit, senior approval will be needed ---payment details will be sent to the customer along with the proposal ---proposal will be sent on email and sms by using SMTP and API settings of application 7) Sales Executive: ---profile of sales executive ---login of sales executive ---sales executive login to his android device ---that android device will sync all the data required 8) Data to sync from sales executive mobile: ---contacts ---call history ---sms ---whatsapp call history ---whatsapp chat history There will be role management for web portal, where admin can create multiple roles for different people. There will be sales team leader, so the teamleader will be able to see all the leads under his team you can check this app: [login to view URL]