LG is using the IFA tradeshow to announce AllJoyn-compatible lightwave ovens and air conditioners, as well as a shiny new smartwatch, but its most interesting announcement is a small after-market sensor that will allow users gain performance data from their existing home appliances in order to spot potential problems. Called the ThinQ, the small circular device will monitor temperature and vibration readings to determine a device’s normal operation, as well as plot that curve against an expected vector from its manufacturer. Aside from this predictive maintenance functionality, LG says that it could allow apps to spot the end of a spin cycle and send a push notification, monitor expiration dates for items in refrigerators, or even enable remote control of…