I need to create a prototype for a new feature of our existing app. I was wondering if there is something out there that I could import the screens from our app into a prototype tool like Sketch or InVision where I could make changes and then present to users.<p>Simply taking screenshots has been frustrating. I need something with layers so it is easier to manipulate the elements on the screen.<p>Any thoughts?
Ask HN: Designers: Any tool for prototyping on top of existing mobile apps?