Youthful Memories on Swarm
Swarm (formerly Foursquare) is an app I have been using since 2010. It is a location-based social network. Back then, I worked for a startup in this space, building a similar application. That is why I kept using it long after I stopped working there.
Working on that app helped me discover interesting places and great food spots in Saigon, as well as many other places I visited.
Foursquare as we knew it is gone, succeeded by Swarm. I still use it today simply for the sake of my youthful memories. It holds onto the photos and the places I have been.