Android and iOS Mobile app for approving tickets and show work done dashboard

Need mobile app for android and ios device. Function 1 This app should be able to show list of invoice ready to be paid and user should easily approve single or multiple invoices in a go. Function 2 App should show simple dashboard of number invoice in different status categories and a drill down shows list of those invoices. User can change status of those invoice from the list. Function 4 User should receive notification of number invoice pending for users action. Function 3 (optional phase 2) From the list of disputed invoice user should have option to send mail to related ppl (from contact) and reply of those emails(from phone) should be captured along with invoices. Rest to be discussed.