I help the military for a day with my invisible cloak. If the military needs information on a certain person; I would find out that said information for them. I would also go behind enemy lines and spy on important people/leaders. When I return I would give them what they need without revealing my identity. I would also be a superhero and call myself Vanish. I would respond to most needs for help but not all of them because I am limited to what I can do.
I would work with Superheros that aren't as powerful as others. Since all I have is an invisibility cloak and fighting skills I would just sneak in and see what needs to be done. I would also help out in hostage situations because the suspects won't be able to see me. Superman would be taking care of all of the major catastrophes, while I would be cleansing the streets of bad guys.