Avare is a free open source "moving map" aviation GPS, A/FD and EFB app for phones or tablets using the Android Operating System.
 The app uses an internal or external GPS to determine location, allowing real-time display of location, heading, speed, distance, and altitude on aviation and topographic charts.
 The user can also access all relevant FAA data and some non-FAA maps and data in flight without data connection, once it has been downloaded to the device.
 Ability to display ADS-B data, and to connect with an auto-pilot or flight simulator can be enabled with add-on free open source Avare apps.
OsmAnd (OpenStreetMap Automated Navigation Directions) is a map and navigation app Android and iOS.
 It uses the OpenStreetMap (OSM) map database for its primary displays, but is an independent app and not endorsed by the OpenStreetMap Foundation.
 It is available in both a free and paid version, the latter unlocks the download limit for offline maps, and provides access to Wikipedia POIs and their description from within the app.
OpenWeatherMap is an online service that provides weather data, including current weather data, forecasts, and historical data to the developers of web services and mobile applications.
 For data sources, it utilizes meteorological broadcast services, raw data from airport weather stations, raw data from radar stations, and raw data from other official weather stations.
 All data is processed by OpenWeatherMap in a way that it attempts to provide accurate online weather forecast data and weather maps, such as those for clouds or precipitation.
 Beyond that, the service is focused on the social aspect by involving weather station owners in connecting to the service and thereby increasing weather data accuracy.
 The ideology is inspired by OpenStreetMap and Wikipedia that make information free and available for everybody.
 It uses OpenStreetMap for display of weather maps.
Google Map Maker is a discontinued mapping and map editing service launched by Google in June 2008.
 In geographies where it is hard to find providers of good map data, user contributions could be used to increase map quality.
 Changes to Google Map Maker were intended to appear on Google Maps only after sufficient review by Google moderators.
 Google Map Maker was used at Google Mapathon events held annually.
A moving map display is a type of navigation system output that, instead of numerically displaying the current geographical coordinates determined by the navigation unit or an heading and distance indication of a certain waypoint, displays the unit's current location at the center of a map.
 As the unit moves around and new coordinates are therefore determined, the map moves to keep its position at the center of the display.
 Mechanical moving map displays using paper charts were first introduced in the 1950s, and became common in some roles during the 1960s.
 Mechanically moved paper maps were replaced by digital maps during the 1970s and 80s, with resolution and detail improving along with computer imagery and the computer memory systems that held the data.
 A common example of a moving map display today is the map display in a smart phone, which uses GPS to determine its current position and then recalls the map data from the device's memory or from the Internet in real time.
Karta GPS is a mobile application developed by Karta Software Technologies Lda a daughter company of NDrive for the Android and iOS operating systems.
 It is distributed for free and pairs open-source map data from OpenStreetMap alongside curated content from Yelp and Foursquare.
Foursquare is a local search-and-discovery service mobile app which provides search results for its users.
 The app provides personalized recommendations of places to go to near a user's current location based on users' "previous browsing history, purchases, or check-in history".
Yelp is an American multinational corporation headquartered in San Francisco, California.
 It develops, hosts and markets Yelp.com and the Yelp mobile app, which publish crowd-sourced reviews about local businesses, as well as the online reservation service Yelp Reservations.
 The company also trains small businesses in how to respond to reviews, hosts social events for reviewers, and provides data about businesses, including health inspection scores.
Vector tiles, tiled vectors or vectiles are packets of geographic data, packaged into pre-defined roughly-square shaped "tiles" for transfer over the web.
 This is an emerging method for delivering styled web maps, combining certain benefits of pre-rendered raster map tiles with vector map data.
 As with the widely used raster tiled web maps, map data is requested by a client as a set of "tiles" corresponding to square areas of land of a pre-defined size and location.
 Unlike raster tiled web maps, however, the server returns vector map data, which has been clipped to the boundaries of each tile, instead of a pre-rendered map image.
Cartographic generalization, or map generalization, is a method for deriving a smaller-scale map from a larger scale map or map data Whether done manually by a cartographer or by a computer or set of algorithms, generalization seeks to abstract spatial information at a high level of detail to information that can be rendered on a map at a lower level of detail.
 For example, we might have the outlines of all of the thousands of buildings in a region, but we wish to make a map of the whole city no more than a few inches wide.
 Instead of throwing out the building information, or trying to render it all at once, we could generalize the data into some sort of outline of the urbanized area of the region.

Question: Karta GPS pairs open-source map data from OpenStreetMap with curated content from Yelp and which other local search-and-discovery service app?
Answer: Foursquare