Before SmallTalk, Comma was an ambitious app that fully structured communication in a non-chat way. It took workflows like On my way and turned them into full functioning app workflows that removed most of the common back-and-forth texting that became tiresome. It also did this for movies and food. Each communication flow began as the sending of a "card," such as an on my way card.
On my way
This card was designed to help coordinate meetups. You could send an on my way card to several people which allowed you to turn on location tracking for a short period of time. The card contained a map of the locations (if shared) of yourself and others on the card. It gave a high level summary of everyone's status (running late, eta 15m, arrived, etc), and gave simple actions to update your status. It also allowed for general commenting for all of those little details that are impossible to fully structure.
Starting the same way as an on my way card, one could invite others to see a movie; however, this card allowed you to browse currently playing movies, see showtimes, and watch trailers. That's not that special, but what is special is that it allowed you to choose the movies and times youd like to see and include them in the card. Others could then add their own movies (by watching trailers the same way you did), and vote on the suggestions anyone else made. This allowed for full negotiation of what to see, when, and where using this card. It was extremely powerful and dense - still the most complete execution of movie planning negotiation we've seen.
Similar to movie planning, food planning allowed people to search for and suggest the restaurants they'd like to eat at. Others on the invited card could vote on those restaurants and add their own suggestions. These cards offered quick actions to call the restaurant, see their reviews on yelp, and look at the menu.