What do you need to know to make your geosocial network?

Question

Social media

What technologies, third-party services, languages ​​should/desired/better be used to create a geosocial network with the ability to create personal marks on the map with time reference and filtering by time and location criteria of marks of other users of the proposed geosocial network (Foursquare with extended functionality)?
PS You need to start from the site, but integration with the application for iOS and Android is also planned.

Answer 1

You need to know one thing: Socialists are already becoming obsolete. You don't need new :)