UI developers and leads from a well-known mobile app development company Toronto reveal that User Interface (UI) works as an essential element of interactions between humans and machines, mobile devices and/or computers. UI focuses on external appearance, looks, layout of a screen on the web or mobile applications. It is in reality the interaction between users and visual elements of a product (buttons, checkboxes, text, placeholders, images and the like). User Interface hence gives the app the look and feel of the product design.