Invoicing Website and Client Portal with App

Seeking a full-stack developer to create an invoicing website and client portal with an associated app. The system should allow builders to invoices clients, and allow them to view and pay invoices, and enable the business to manage client information and send notifications. integrate a payment system. The builder should be able to add photos with any payment request. The app should be user-friendly and accessible on both iOS and Android platforms. Experience with web and mobile app development is essential.