Mr. Ghost Smartphone EMF Detector
Do I believe in ghosts? Well, I believe something drank half of those empty Bud Light Lime bottles strewn across my living room floor because I couldn't have possibly blown through three 6-packs on my own. And before you say anything, no, it wasn't. My mama prefers red wine. Plus, the needle on this EMF detector I hooked up to my iPhone is going nuts pointing at my closet. Which, if it's accurate, is kind of a dumb place for a ghost to hang out since he's invisible no matter where he chills, and my new Dr. Claw chair is way more comfortable than the S&...stuff I have in the closet.
ThinkGeek's plug-and-play EMF Detector connects to iPhones and, along with its free gyroscope-enabled app, points in the direction and reads out the frequency of electromagnetic fields emanating from spooooooky places like...well...most probably your TV, video game console, or alarm clock. The EMF attachment can also record detected signals as audio for use in creeping out younger siblings or the highly gullible.
Mr. Ghost works with iPhone versions 4 and up, iPad versions 2 and up, and iPod Touch 4/5. Since most Android devices are actually possessed and operated by deceased spirits, the EMF Detector's compatibility with them will be hit or miss.