iRide?

Taken from Rapha.

Developed for road cyclists, Rapha Rendezvous has been designed to make meeting up for group rides easier. Invite other riders and observe them in real time making progress to the rendezvous point on a map. No more hanging around for friends, failed phone calls, SMS annoyances or scrolling hundreds of emails, Rapha Rendezvous makes meeting for rides quick and easy, giving you more time on the bike.