Oral presentation is one of the most widely used methods in assessing student learning outcomes of content comprehension and communication skills. Nevertheless, both students and teachers face challenges in optimizing the benefits of such learning activity. From students' perspective, they only receive a letter grade but no feedback from the audience (teacher and classmates). From teachers' perspective, students keep making the same mistakes throughout their course of study. Besides, students' engagement in classmates' presentations is problematic. Our team developed an app “Gongyeh 講嘢”, also a web platform, to address these issues through students' presentation video recording and real-time online audience feedback. The main features of the Gongyeh app include: (1) a presenter starts the video recording with his/her mobile device and thus the audience can start giving real-time feedback; (2) three categories of feedback (open comments, questions preset by presenter, and assessment rubrics preset by teacher); (3) only the presenter and teacher have the recorded video and feedback; and (4) the feedback given by the audience is anonymous to the presenter (just known to the teacher) and time-synchronized with the video. So far, 42 teachers (33 PolyU, 1 HKCC, 4 HKU, 3 EdUHK, and 1 from a high school in Myanmar) and 1,510 students used the app. The project team received very positive feedback, from both students and teachers, on the effectiveness of the app in helping students improve their presentation skills and enhancing students' engagement in classmates' presentations.