Yes it was necessary. I don't know how to do design and CSS and there's no money made or invested into it. I tried putting together a design but it looked shit and never worked very well.
Convenient to you and necessary are not synonyms. There is an Internet full of free (beer and/or speech, your call), legal, pretty designs that you can use to your heart's content.
I recommend anything by Styleshout (great web 2.0y designs), MultiFlex (more traditional, a little boring by default but clean and fits just about anything), and several of the designs on oswd.org for projects which don't have the budget for a custom design. I actually ran a profitable business off of an OSWD template for almost two years:
I mean, Jesus, it's a simple web app. It shouldn't take you more than a few hours to come up with your own design and code.