Use my device as laser pointer I'm not sure if this is possible, but knowing that is possible to use the device as mouse I think this should also be possible: Somehow connect the phone with a PC, then in the place you touch from the phone, in the computer should appear a red dot (or something).

Is there any app for this?? Is it possible?
One solution would be to use a program such as TeamViewer and set the computer's cursor to a red dot, or just use the regular cursor. Teamviewer has a program that runs on the computer, and an app that allows you to control the computer from your phone. I think it would work quite well for what you have in mind.