Hi,
I have gone through your post here and have a clear understanding of your requirement.
We have done several location based apps in the past and we have the expertise to design , develop and deliver this as per your requirements.
For the app we will need :
1) A custom web server to pull data of google , foursquare , etc and store in the db on the server app.
2) API's for pulling the data off the server.
3) Mobile app on the user side.
Please read your PMB for more details.
Cheers,
Rahul.