how can i make my phone camera a spy camera Answered

I want to make a spy cam with a phone camera i even tried but didint work out so well. That way i can have spy camera in my class room is it possible to connect those 9v battery to a dissasmbled phone camera. Anothere qestion is if i manage to do this connectin is it olso possible to add a memory to the camera so that the camera will transmit the video o the momory or should i just make a bluetooth connection. I hope this question will bring some answears Thank you very much and my respects. Im waiting for a reply im most of the day online. Dragos