Hello sir, I've been working with firebase for android for two years, and I can help you to build that app within 2 days with an awesome user interface and performance. Hire me!
If you have a design for this project, I'll follow you, and skip the design step. Otherwise, I will create user interface by your requirement.
If you want to use your firebase account, I think that it's better when you type your account when I develope the application ( of course using TeamViewer to assure about private ).