Gesture sensor is used to detect and recognize meaningful gestures from the parts of the human body such as hands, arms, face, and head. Most of the gesture sensors are mainly based on image sensor. Image sensor technologies have been focused on depth information. However, after the advent of smart phone, other technologies such as touch IC and proximity sensor are entering in the gesture sensing market with low power consumption. Mobile devices need high accuracy and low power consumption. This white paper provides a survey on gesture sensor and its trends for mobile devices. This paper also deals with existing challenges and future research possibilities.