Invoices are the one feature that falls behind the curtain, and only appears when you’re either building a strict invoicing app on its own, or when you are offering to do invoicing tasks within an application that functions as a platform. The invoicing application concept here from Monika Majkowska focuses on building an invoicing app, but this design could very well work in a situation where you wish to incorporate such a design concept into an already existing app that requires to conclude tasks related to invoices. The design is built on top of a dark color scheme, and has the design elements to display individual invoices for users, buttons to delete and print invoices, and also a statistics report for how the invoices are bringing in revenue.