UniDoodle is a multi-platform, smart device based student response system that provides a freeform-style input using sketch capabilities. This offers significant advantages over existing student response systems, such as Clickers, which are limited in their input capabilities and generally only allow for a multiple-choice selection. In contrast, UniDoodle caters for writing equations, drawing diagrams, annotating figures or any form of graphical input. The key focus of this paper is to evaluate the use of this response system in an active classroom environment over an extended period of time. Fundamentally, we wish to address the following key questions in relation to UniDoodle: do students find it easy to use; do they find it beneficial to their own learning; does the lecturer find the sketch-based student responses beneficial; and how does the use of this response system affect the typical classroom lecture? Here, UniDoodle was used in a first year Systems and Control module, in the Dept. of Electronic Engineering in Maynooth University, for the duration of an entire semester. This paper will present an outline of the UniDoodle system and its key features, details of the actual evaluation with some sample questions, and a summary of the student and lecturer feedback obtained.