Electronic devices in a system may be controlled by a user. The user may have one or more wearable devices or other devices. A user's device may be used by the user in identifying a target electronic device of interest among the electronic devices in the system. The target electronic device may be identified using a gaze tracking sensor that senses the user's point-of-gaze, an orientation sensor that detects a direction in which the user's device is pointed, or other sensor circuitry. Visual feedback, audio feedback, and/or haptic feedback may be provided to the user to confirm which electronic device has been identified as a target electronic device of interest. User input may be gathered by sensors and used in adjusting operating parameters in the target electronic device of interest. Health monitoring operations and other operations may also be performed.