Face 2 Face is a 2016 film about teen friendship that unfolds entirely on Skype. You can watch it on Prime or Youtube.
Because the film is realistic, it's less aesthetically experimental, but it's a good example of what it's like for characters to build a relationship with the camera. It also finds creative ways to bring plot points from the outside world into the main bedroom setting, like we sometimes see in a two-hander play.