I understand that you need an App mockup but wondering, if you can please provide me more details, I can then instruct my Designer team to present few mock-up design options of the Home Page for you to see and get your feedback, once you see the mock-up design options, you can then provide us detailed feedback/changes/comments, so our Designers can revise the selected mock-up. Our Designer's team can do as many revisions as you want, till you're happy/satisfied.
Our current bid is just a placeholder to submit the proposal, as we still need to finalize the scope of work.
Look forward to hearing from you.
Regards,
YK
LEADconcept