iOS Payment Approval App

I'm looking for a basic iOS app to manage payment approvals within my small business (10 employees). The app should facilitate a multi-level approval process for payment vouchers. Payment voucher will be raised by manager and approved by other users.

Key Features:
- User Roles: Manager, Internal Auditor, Accounting Manager, CEO
- Role-specific dashboards
- Confirmation actions for each role
- Upload/download Payment Vouchers/Invoices
- Push notifications for action alerts

Ideal Skills and Experience:
- iOS app development
- Experience with approval workflows
- Familiarity with push notification integration
- UI/UX design for role-specific dashboards

Please include a work-flow and technical details in your submission, along with your contact email.