Lab orientation is a vital part of learning for new students entering the university, as it provides the students with all the necessary and important information about the lab. The current orientation is manual, tedious, suffers from logistical constraints, lacks engagement, and provides no way to assess that outcomes have been achieved. This is also supported by the results of a student survey which revealed students' dissatisfaction with current process of orientation. This study presents the design and development of a sample augmented reality mobile application, AR-LabOr, for the lab orientation that helps students in a quick and easy adaptation to the lab environment by familiarizing them with the lab equipment, staff, and safety rules in a fun and interactive manner. This application makes use of marker-less augmented reality technology and a blend of multimedia information such as sound, text, images, and videos that are superimposed on real-world contents. An experiment with 56 students showed that they found the novel method of orientation using the application more engaging than the traditional instructor-led method. Students also found the application to be more supportive, motivating, and that it helped them in better understanding the lab equipment.