Hello everybody!
My name is Dmitriy, i've got a motocentr named Kvadromania. It's not far from Moscow, Russia. Couple a monthes ago we developed application for smartphones on android, named QuadMaps. You can find it on Google Play Market. Sorry we don't have iOS version still.
The main thing of Quadmaps is that you can see every atv rider where you want to. Of course if he is online.

What else this app can:

• Make new contacts, exchange messages
• Appoint meeting places
• Ask for help if got stuck or broken
• Scrounge around for racing together
• Mark points of interest, add their photos and locations on the map
• Create private rooms
• Attend rooms created by other members and earn points
• Arrange competitions
• Switch to invisible mode to keep secret all your gear's storage location
• Create points in offline mode

Please check it out, and tell me what do you think about it.
Just write quadmaps in google play market and you'll find it.