This app would be designed for golf specifically. The purpose of the app is to quickly post tee times or golf tournaments to different groups of friends based on how they know each other. For instance, sometimes it matters which friends you invite to play golf with as they may not all get along, or they might want to see who's playing before they choose to accept. This save the time of texting all your friends to see who can play golf at what time, where it's at, and who's all playing. Once they get the notification of the tee time, they can see the time, the location of the course as well as who has all signed up to play.
Also, as the user, you have the ability to see who is playing, where they are playing, and if they need a fourth player. Ability to grow your group of people that you would like to golf with.
There are more attributes to add, but this is the basics.