When did Foursquare change to Swarm?

Can you elaborate on the timeline of when Foursquare made the decision to transition from its original platform to Swarm? What were some of the key factors that influenced this change, and how did the company communicate this shift to its users? Was there a specific moment or announcement that marked the official transition, or was it a gradual process? I'm curious about the overall strategy behind this move and how it fits into the larger narrative of Foursquare's evolution in the tech and finance space.