I was a loyal Foursquare user. I checked-in daily & posted thoughtful reviews of restaurants, parks, hotels, theaters, and wherever else I went. I met friends through Foursquare and generally had a great time with the app.
In May 2014 Foursquare removed check-ins and transformed the app into a lesser imitation of Yelp (using the accumulated reviews from Foursquare's loyal audience.)
Foursquare's users felt betrayed that their reviews were used but what they once loved about the app was removed. Here's how that worked out:
An analysis of the popularity of Foursquare over time using Google Trends, April 15, 2015
Today Foursquare is barely more popular than when it launched.