My client, inspired by Trello and Todoist, decided to make his own system for managing small and medium business projects. I started by research of the references and competitors, eventually putting together an UI mindmap.
In a few weeks I prepared about 20 low-fidelity prototypes in Balsamiq Mockups with comments and mechanics of interface elements. Users of the system — employees of companies and their clients — can manage the progress of work, communicate with each other, send files and automatically pay for work.