We are frequently switching between devices, and currently we have to unlock most of them. Ideally such devices should be seamlessly accessible and not require an unlock action. We introduce PickRing, a wearable sensor that allows seamless interaction with devices through predicting the intention to interact with them through the device’s pick-up detection. A cross-correlation between the ring and the device’s motion is used as basis for identifying the intention of device usage. In an experiment, we found that the pick-up detection using PickRing cost neither additional effort nor time when comparing it with the pure pick-up action, while it has more hedonic qualities and is rated to be more attractive than a standard smartphone technique. Thus, PickRing can reduce the overhead in using device through seamlessly activating mobile and ubiquitous computers.