The Buddy Flight™ is a extension of Pitlab FPV System supporting flying in a group. On the radar view in the OSD, pilot can see position of up to 6 other planes. If you fly with camera and goggle you know how hard is to locate other plane in space. Pilot can see planes in front of it's plane on similar altitude and short distance. With Buddy Flight™ you can see other planes up to several kilometers around you on all altitudes, even in a clouds.
Other planes are presented on radar screen as markers with user defined letter (A-Z). If the buddy plane is higher (20-100m) then our, it's marker is combined with triangle symbol pointing up. If difference of altitude is bigger, the double triangle is presented. Similar when buddy plane is below us - like on above video - we can see it as a single or double triangle pointing down.
Flying with a friend it is great fun, but the system has also other important safety features. First is anti-collision, because you can see planes flying on you even from back side. Other feature is searching a lost or crashed model. System remember last position of the all planes and if one of them will stop transmitting it's position, other planes will see it's last position alternating with "X" letter and can fly to this point.
There is thread about Buddy Flight ™ on RC Groups.