A new, creepily awesome Android application developed by two Microsoft interns turns Android smartphone cameras into full-on spy machines. The app, called TagSense, relies on smartphone sensors to automatically tag photographs with the identities and activities of whoever’s in them. No human input is required.

Although it also makes use of facial recognition technology, TagSense mainly relies on the myriad peripherals integrated into the average smartphone. Android phones’ built-in accelerometers are used to determine the exact physical activity a picture subject is involved in, while light sensors in the camera are used to determine weather conditions outside in conjunction with location data obtained via GPS. The phones’ microphones can then determine whether the picture subject is talking, laughing, crying, or silent. All this information is then tagged onto the photos.

But the kicker for TagSense is that it is designed to tap into information stored on other, nearby smartphones. The application will be able to interact with data stored on adjacent phones that are also using the app, enabling collaborative tagging and verification of photo subjects’ identities. The application’s creators claim that there will be a strict opt-in requirement for use of that particular feature.

According to co-creator Chaun Qin, “phones have many different kinds of sensors that you can take advantage of. […] They collect diverse information like motion, orientation, location, sound and light. By putting all that information together, you can sense the setting of a photograph and describe its attributes.”

Both Qin and co-creator Xuan Bao are currently summer interns for Microsoft Research. Bao and Qin are working on computer science PhDs at the University of South Carolina and Duke University respectively. They both collaborated on the project with Romit Roy Choudhury, a professor at Duke University.

Qin and Bao’s application also pioneers technology that could be of interest to everyone from tech firms to the media to the military. An excerpt from their technical paper gives an idea of the possibilities: