Build a Website

I am low balling this project because I am not yet sure what direction is best. Consider this consulting to identify the best course of action. I have a membership group of several businesses that are willing to accept our coupons. To help members to identify participating business, I was planning to pay for an existing Business Directory android iphone capable app that has geo map location ability. But was thinking that google maps may be able to handle it, but do not know enough about it. Maybe some sort of sharing of tags that id's participation business, so that when I look for a restaurant on maps or the iphone equivalent I can easily see who accepts coupons. If this is too vague ask any questions you like. If you come up with a solution that requires more time I will initiate a new project based on what solution has been identified.