Virtual Laser Pointer

It would be nice if you could install a "a virtual laser pointer" which can be activated and can be controlled by one party in order to point out while a conversation. Use case is remote assistance , if somebody has a problem the other party can explain how to solve the problem and the laser pointer would help to explain. For example you share the screen of the front camera of an IOS device with a PC and the PC operator can point out at the IOS camera screen a certain position. For that case it would also be necessary to bring the IOS screen on the IOS device on full size instead of the PC screen of the opposite party.