Develop a Mac Application

I would like to create a mobile app that will allow people to search on a google map for their closest pub. Pubs will need to be able to upload their location, an image of the pub and a summary of its facilities. Users will need to be able to rate the pub and be given google map directions from their location to the pub. I am living in London and will only require it to be available in this city. I want a very simple yet functional design.