Tinder, Instagram directly interfaces with Facebook. Beyond your NearBy Places, they takes into account many important factors when arranging your list of potential matches each time you open the application such as Soft Reset, Hard Reset, swipe left, swipe right, gender, age etc. Hence I think this should not be our main concern to differentiate this app with Tinder or Instagram, rather than I think there have a bit fault in Places API which is used in your app
I have got that the NearByPlaces API is not working properly on the CheckIn iOS app. It need to be more optimized since the application is not being properly captured the nearest places. It uses Apple MapKit and CoreLocation framework to do all the work about location
It seems when you are first calling ShowNearByLocation as I can only assume it in your callback function( loop looks odd). I guess you are calling it after you create the initial marker? If you are not then your code you have used never gets called
As the solution, there need to be use the Places Web Service API, this should help you get the functionality you're looking for. whereas it allows you to query for place information on a variety of categories, such as: establishments, prominent points of interest, geographic locations, and more. You can search for places either by proximity or a text string. A Place Search returns a list of places along with summary information about each place; additional information is available via a Place Details query