What makes a bad app design?
Poor information architecture results in bad app design as the layout and structure of your app's information aren't easy to understand or use. As a result, users will be confused about navigating your app and will likely end up abandoning it.
What is the effect of poor user interface design?
Not only does the bad UI design totally destroy the creativity behind the designers, but also delivers misunderstanding info to users. All of those will altogether bring users a sense of confusion, frustration and even anger.