The ability to immerse yourself, with confidence, into an app comes about because you're willing to give yourself over to it, to trust it with that which you tirelessly create. You believe the developers aren't considering you, but the royal You they have absolute respect for.
This is similar to our give over of faith to the participants in a play or film. The "fourth wall" as its known in these activities of immersion, in which it's said that the actors pretend they can't see through that wall to their audience, but are obviously considering the entire audience, hence their efforts.
In playing games we're constantly (as the audience and player) breaking that fourth rule by our engagement with the room of the game and its characters and entities. But the manner in which the game treats us as a respected participant can be seen as an equivalently important property in terms of providing immersion and the trust required to consistently and fully immerse ourselves in the world of a game.
Similarly, in a creative app, we're seeking the confidence to immerse ourselves in creating content with our passion for writing, drawing, coding, data entry or whatever it might be we do secure in the knowledge the developers have considered the royal "We". We value our time and creative output more than the cost of software (in most cases), so we need to confidently commit to trusting the app to respect our immersion into it as a tool for our creative endeavours.
So I'd use the ideas of "suspension of disbelief" (in the prowess of programmers and in the fears of the fragility of software) to describe this phenomenon.