Ensuring accessibility on mobile apps

• Vision - Users should be able to magnify content, enable screen readers, adjust color contrast or use other accessibility features built into their device OS.
• Hearing - Captioning and transcripts should be provided for audio content. Tones and vibrations can alert users to notifications.
• Mobility - Apps need to be fully operable via gestures or assistive devices. Button size and spacing should allow easy navigation.
• Cognition - Design should be intuitive and content written clearly. Instructions should be simple and options easy to understand.

• Web Content Accessibility Guidelines (WCAG) 2.1 - Published by the W3C, this is the current international standard for web accessibility. The A and AA criteria can be applied to mobile.
• Revised Section 508 Standards - U.S. federal accessibility standards that now integrate WCAG 2.0. Useful for public sector apps.
• EN 301 549 - The European standard for accessibility requirements suitable for public procurement of ICT products and services.
• Apple Accessibility Guidelines - Apple provides comprehensive tech-specific guidelines for supporting accessibility on iOS and macOS.
• Google Material Design Accessibility Guidelines - Google's guidelines for building accessible Android apps using Material Design.

• Semantic HTML ensures elements have proper tags and structure so screen readers can understand content.
• ARIA attributes can be added to provide further meanings like labels, navigation landmarks and error messages.

• Foreground and background colors should have a minimum 4.5:1 contrast ratio.
• Color should not be used as the sole way to convey information.

• Font size needs to be high enough to allow magnification up to 200%.
• Scaling text should not require horizontal scrolling at any zoom level.
• Support dynamic type for user-adjustable font sizes.

• All elements need to be reachable via keyboard navigation.
• Visual focus indicators are required to see what's currently selected.
• Logical tab order allows efficient navigation between elements.

• Tap targets need to be spaced appropriately and large enough.
• Targets less than 24px square may require extra spacing between.

• Use minimal and standard gestures. Rely on common interactions like tap, swipe, pinch, etc.
• Provide visual cues and affordances to indicate available gestures.

• Images, videos and audio require text alternatives like captions and transcripts.
• Media cannot auto-play. User controls are required.

• Avoid justified text alignment. Use easy to read fonts.
• Make line height and paragraph spacing sufficient.
• Italicized text is harder to read and should be avoided.

• Clearly communicate loading, errors, notifications and other status.
• Form validations and error messages need to be screen reader accessible.

• Automated testing - Use auditing apps and developer tools to programmatically scan for accessibility issues. Examples include Accessibility Scanner for Android and Accessibility Inspector for iOS.
• Manual testing - Physically interact with the app on mobile to confirm elements are readable, usable and navigable. Test with assistive technology like screen readers.
• User testing - Have people with various disabilities test the app and provide feedback. This offers real-world validation.
• Guideline validation - Review against WCAG or other standards to confirm compliance criteria are met.

• Clean layout - Content should be well-organized with clear separation between elements. Remove unnecessary complexity.
• Intuitive design - Create familiar, logical flows that are easy for all users to understand. Strive for consistency.
• Readable content - Use plain language. Be concise and descriptive for screen readers. Format content clearly.
• Strong information architecture - Group related content meaningfully. Use context-specific headings and landmarks.
• Customization - Offer options to customize font, contrast, notifications and other elements to suit user needs.
• Supportive patterns - Use input masks, validations and smart defaults to aid completion. Provide help information.
• Task-focused features - Streamline complex tasks into simple, efficient flows. Minimize cognitive load.

1. Wider reach - Apps are usable by the over 1 billion people worldwide with disabilities. This expands the addressable market.
2. Increased adoption - Accessible apps have better ratings and reviews. They demonstrate care for users, building brand loyalty.
3. Lower development costs - Accessibility issues are cheaper to fix when addressed early in development. Retrofitting apps is expensive.
4. Legal compliance - Many places require apps to meet accessibility standards. This avoids litigation risk.
5. Competitive advantage - As consumers demand accessibility, it becomes a market differentiator.
6. Improved UX for all - More users can complete tasks easily. This raises conversion, sales and ROI.

• Older OS versions may lack newer accessibility features. Weigh limiting OS support vs having fewer options.
• There is often tension between simplicity and customization. Allow some user adjustments, but not overwhelming complexity.
• Excessive testing and validation takes resources. Strike a balance between being robust and efficient.
• Accessibility best practices continue advancing. Decide when to support something new vs relying on existing standards.

• Adding accessibility late in development is difficult. However, planning everything up front risks missing needs of real users.

• Advanced AI - Smart interfaces that adapt to individual user needs show promise for improving accessibility.
• Predictive design - Big data and analytics can better predict optimal designs for people with disabilities.
• New interaction modes - Voice, AR/VR and wearables open possibilities for more accessible controls.
• Regulatory mandates - More governments are enacting legal standards for mobile app accessibility.
• Industry collaboration - Groups like the Mobile Accessibility Alliance aim to advance standards and best practices.
• Inclusive design culture - More designers and developers receive accessibility training and prioritize it.

Summary and Key Takeaways

• Follow established guidelines like WCAG 2.1 throughout design and development.
• Carefully implement technical elements for vision, hearing, mobility and cognition.
• Conduct extensive automated and user testing to identify issues.
• Create an intuitive, inclusive user experience that works for everyone.
• Make accessibility a priority from the very start of mobile projects.
• There are challenges to balance when optimizing for accessibility.
• Enabling more people to use apps has benefits for both businesses and society.