This is a music specific post but can be adapted for your own context.
Pupil and lesson observation feedback this term have highlighted the use of a simple webcam as a useful tool to aid learning.
As a music teacher I find it very quick and easy to use the webcam over the piano to demonstrate the task, hand position, chords and also easy mistakes to avoid. This is projected onto the screen for students to see, both at desks and at keyboards. It helps with visual prompts, focus and engagement and also a demonstration by the teacher modelling good and bad examples can really help students make progress.
It is always followed up by individual verbal feedback and personalised demonstrations when needed but as a tool, a simple webcam has really helped progress and confidence in my music classroom.
(140 words whoops!)