I like to produce app wireframes like this, as everyone can see what needs to go where from a technical perspective and get a rough idea of how the app will look. Once the functionality is agreed on, the cost to develop it can be confirmed before the client is promised anything. A wireframe like this would likely undergo several adjustments before laying the UI design over the top. When sharing designs like this with developers it’s always useful to get their take on it – sometimes they may suggest a tweak that could streamline things further.
The image below shows the back-end connectivity and the client admin screen.