Mobile App Screen Design

This guide focuses on the practical aspects of designing mobile app screens, covering typography, color theory, layout principles, and creating specific design elements. Learn to apply visual design principles that create polished, professional mobile interfaces.

Objectives

By the end of this guide, you will be able to:

• Understand the principles of designing mobile app screens
• Learn to apply typography, color theory, layout, and composition
• Create design elements like buttons, logos, and color palettes

Understanding Mobile Screen Design Principles

Successful mobile screen design is built on fundamental principles that ensure usability, clarity, and visual appeal across all screens in your application.

Core Design Principles

Consistency

• Maintain visual consistency across screens using design systems
• Use reusable components (buttons, inputs, etc.)

Clarity

• Ensure information is easy to read and navigate

Simplicity

• Avoid overwhelming the user with unnecessary details

Frame Sizes and Device Considerations

Understanding device specifications and constraints is essential for creating designs that work across different screen sizes and resolutions.

Common Device Screen Sizes

• iPhone 11 Pro: 375x812 px
• Pixel 6: 412x915 px
• Use Figma's preset frames for quick setup

Safe Areas and Margins

• Respect device-specific guidelines for notches and navigation bars
• Apple's guidelines: 44px minimum safe area for interactive elements

Applying Typography in Mobile Design

Typography plays a crucial role in mobile usability, where readability must be optimized for small screens and various viewing conditions.

Key Typography Guidelines

Font Size Standards

• Apple recommends: Minimum of 17px for body text
• Google suggests: 16sp for Android apps

Establishing Hierarchy

• Headings: Bold and larger font size
• Body text: Regular weight and smaller font

Best Practices

• Avoid using more than two typefaces
• Adjust line spacing and letter spacing for legibility

Using Color Effectively in Mobile Apps

Color choices significantly impact both aesthetics and functionality in mobile applications, affecting everything from brand perception to accessibility.

Color Theory Refresher

• Use complementary or analogous colors for visual harmony
• Use vibrant colors for call-to-action elements

Accessibility Guidelines

• Ensure sufficient contrast ratios (WCAG recommends 4.5:1 for text)

Best Practices

• Use brand colors sparingly to avoid overwhelming users
• Implement light and dark themes following platform guidelines

Layout and Composition

Effective layout and composition create visual hierarchy and guide users through your application's content and functionality.

Grid Systems

• Use an 8-point grid system for spacing and alignment (Material Design standard)

Alignment and Balance

• Align elements to maintain symmetry and organization

Visual Hierarchy

• Place the most important content at the top
• Use size and color to draw attention to key elements

Spacing

• Maintain consistent padding and margins for a clean design

Designing Interactive Elements

Interactive elements must be designed with touch interfaces in mind, ensuring they are accessible and provide clear feedback to users.

Button Design

• Minimum touch target size: 48x48 dp (Google) or 44x44 px (Apple)
• Use shadows, gradients, or borders to indicate interactivity

Icons and Labels

• Pair icons with text for clarity
• Use simple and recognizable iconography

Feedback Mechanisms

• Highlight button states: normal, hover, pressed, and disabled

Accessibility in Mobile Screen Design

Accessibility considerations must be built into the design process from the beginning, ensuring your app is usable by people with diverse abilities.

Key Considerations

Contrast

• Use tools to verify text-background contrast

Dynamic Text

• Allow font size scaling for accessibility

Screen Readers

• Include descriptive alt text and accessible labels

Touch-Friendly Design

• Ensure adequate spacing for users with motor impairments

Industry Standards

• Follow Apple's Accessibility Guidelines and Google's Material Design Accessibility principles

Visual Design for Key Screens

Different screen types require specific design considerations to optimize user experience and task completion.

Home Screen

• Display key information and actions prominently

Forms (e.g., Adding Expenses)

• Use clear labels, ample spacing, and visible error messages

Summary Screen

• Visualize data with charts and tables for quick comprehension

Example Layouts

• Side-by-side examples of poorly designed vs. well-designed screens

Finalizing Design Elements

Creating a comprehensive design system ensures consistency and efficiency throughout the development process.

Style Guide Components

• Define color palettes, typography, and reusable components

Icons and Logos

• Create scalable icons and logos that align with brand identity

Prototype Integration

• Prepare design files for prototyping tools like Figma or Adobe XD

Example Deliverables

Buttons

• Primary, secondary, and disabled states

Input Fields

• Default, focused, and error states

Charts

• Bar, line, and pie chart examples

The Importance of Prototyping

Prototyping is the process of creating a model or simulation of the final product, allowing designers to test and visualize how users will interact with the app. It’s a vital step in the design process to ensure that the app’s user experience is smooth and intuitive.

Figma’s Prototyping Features

Figma’s prototyping features make it easy to create interactive designs without needing to write any code. Let’s explore some of the powerful tools available:

Interactive Components

What is it?
These components, like buttons, links, and forms, allow you to define interactions that users will experience in the final product.

Example:
A button that, when clicked, takes users to the next page in the app or opens a modal window.

Overlay and Scrolling

What is it?
Overlays can be used for modals, dropdowns, or pop-up menus, while scrolling areas allow designers to create scrollable content areas within a frame.

Example:
A shopping cart in a sidebar that users can open and close without navigating away from the page.

Device Preview

What is it?
You can preview how your prototype will appear on various devices, such as mobile, tablet, and desktop, to ensure responsiveness and usability.

Example:
Testing a mobile version of the prototype on a smartphone screen to ensure all buttons and text are properly aligned.

Transitions and Animations

What is it?
Transitions define how one screen moves to another, while animations bring life to the design.

Example:
In an e-commerce app, when a user clicks on a product, it might zoom in or slide into a larger view for better visibility.

Prototype Integration

• Prepare design files for prototyping tools like Figma or Adobe XD

Example Deliverables

Buttons

• Primary, secondary, and disabled states

Input Fields

• Default, focused, and error states

Charts

• Bar, line, and pie chart examples