Microsoft invested $15 million in Foursquare earlier this year, and now the software maker is using the location data to improve its Cortana digital assistant. Windows Phone 8.1 users have started seeing prompts to add nearby suggested places into Cortana’s Notebook of features recently. The new feature simply surfaces nearby Foursquare locations that are popular, including restaurants, bars, and places of interest. Foursquare’s suggestions appear in cards alongside other Cortana interests, and selecting one will immediately launch the Foursquare app to show a more detailed view of the place.