Revisit Blacktop and TrackinU Universal, two early iPhone apps that turned check-ins and geotagged tweets into maps of a journey.

Before today’s travel journals, early iPhone apps experimented with turning social posts into a record of a trip. Our September 2010 article, “Join the Journey,” featured two such apps: Blacktop and TrackinU Universal . This historical guide identifies both and explains what the original links referred to.

Blacktop: a journey built from check-ins

Our archived coverage described Blacktop as a way to group Foursquare and Facebook check-ins into trips. People could add photos and comments to places along the route, then share the journey on Facebook. The listing identified Zenbe, Inc. as the seller and Apple app ID 386017063 .

The appeal was a simple one: a collection of individual check-ins could become a story about a night out or a vacation.…