You may already have prduced some sketches/mock-ups (see the next section) in the process of pulling together your ideas and, if so, that’s great. If you haven’t thought about the layout of your app yet though you should star t to consider this now as well (you’ll probably end up changing these as you go along but you should have a starting point).
All you need to do is go through each page of your app, and divide up the available space with all the content and functionality features you wrote down in the previous section. Don’t worry if you not 100% sure at this stage, this step on from brainstorming will help you get ideas more in order and can easily be changed as the project develops.
Pencil and paper is probably best for now, you can always scan or re-create on some digital tool later. Once you’ve done every page you’ll need to take a look at design.