I'm sure you worked very hard on this. It works well for what it is, and it looks polished. This would be something need to include in a portfolio or work sample. However, if you're serious about starting a business, I'd caution against it.

1. There are already a ton of similar sites. I see one on HN about once a month.

2. The "Icon + Text" approach is rather limited. I think it targets the very bottom of the market, who aren't very savvy about branding. I suspect that market segment is already well served by free logo services.

Wishing you the best of luck anyway.

EDIT: Didn't realize this was an addon to an existing website builder, and not a stand alone product. In that case, forget what I said. This could be a useful value-add

This is a service by http://www.b12.io/, right?

Speaking about that, how can I get just the design customization instead of a monthly service that includes hosting? I can do hosting, that's easy, I can't do design.

Nice! This looks just like https://logojoy.com/ which makes a lot of money doing this

This is great! I just used it to make 2 stickers.